JP2010131846A - Method of manufacturing fiber-reinforced plastic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of transferring a preform which shows excellence in handleability and transferring easiness by bonding a preform to a transfer jig itself via a resin material possessed by a preform base material and transferring the preform, and which can transfer the preform to a molding mold by keeping a molding shape of the preform without damaging a quality of the preform and can arrange the preform precisely at a predetermined position and every time at the same position. <P>SOLUTION: The preform 3 having the resin material on the surface of the reinforcing fiber base material is temporarily bonded to the preform transfer jig 2 via the resin material. In the state that the preform 3 is transferred to and mounted in the molding mold. Then the preform transfer jig 2 is removed from the preform 3, and is arranged in the molding mold. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a fiber reinforced plastic, which is characterized by the conveyance of a preform, which is an intermediate material when producing a fiber reinforced plastic, and can stably produce the fiber reinforced plastic with good reproducibility. In particular, a preform produced by a shaping mold or a shaping apparatus is transported to a molding die without impairing its shape and quality, and is placed in a predetermined position of the molding die with high accuracy, thereby producing a high-quality fiber. The present invention relates to a fiber reinforced plastic manufacturing method for obtaining reinforced plastic.

  A preform made of reinforcing fibers is put into a mold, a liquid resin is injected into the mold and impregnated into the preform, and then heated and cured to obtain a fiber reinforced plastic, or set on a mold, Covering the set preform with a film, vacuuming the inside of the film, injecting the matrix resin into the preform, impregnating the preform with the resin, and then heat-curing a vacuum assisted RTM (hereinafter referred to as VaRTM method) molding method, etc. In recent years, it has become a mainstream method for producing excellent fiber-reinforced plastics. These molding methods have an advantage that a large member having a complicated shape can be molded in a short time.

  In order to manufacture high-quality and complex-shaped fiber-reinforced plastics, it is necessary to produce high-quality preforms, and various preform manufacturing techniques have been developed.

  Patent Document 1 discloses a method for continuously, accurately and efficiently manufacturing a long preform having a U-shaped cross section. According to this method, the laminate comprising the reinforcing fiber base is disposed on the inner mold having the U-shaped inner shape, and the laminate is surrounded by at least two outer shapes that can be pressed against the inner mold. A preform having a U-shaped cross-sectional shape can be produced by pressing the laminated body against the inner mold using a mold. By repeatedly performing mold clamping and mold opening by the inner mold and the outer mold and conveying the laminated body to the mold, a preform can be continuously produced. Furthermore, by interposing a U-shaped continuous sheet-like member between the laminated body and the outer mold, it is possible to prevent the laminated body from being caught in the gap between the outer molds, and an excellent preform. Can be manufactured.

  The preform manufactured by the shaping apparatus as described above needs to be transported and disposed on a mold in order to inject and cure the resin.

  However, since the preform is composed of substantially reinforcing fibers before the matrix resin is injected and cured, it is inferior in shape retention and easily deformed. For this reason, there is a problem that the quality of the preform deteriorates due to the preform being deformed by its own weight during conveyance. In addition, since the preform has poor shape retention as described above, it is difficult to accurately place the preform on the mold, and the resin is injected and cured in a state where the preform is placed at a location deviated from the predetermined placement position. As a result, the performance and shape of the obtained molded member differ from one molded member to another, and there is a problem that reproducibility is not ensured.

  Patent Document 2 discloses a method of manufacturing a long preform having a cross-sectional shape such as C-type or L-type using a shaping die. According to this method, a laminated body composed of a reinforcing fiber substrate having a thermoplastic resin on the surface is placed on a shaping mold, covered with a bag material, sealed, and the inside is vacuum-sucked to thereby reduce atmospheric pressure. In the production of a preform by bonding and integrating the reinforcing fiber bases via the thermoplastic resin by heating in a state where the laminate is shaped using the heating, between the reinforcing fiber bases by heating. A method for producing a preform having excellent quality by unsealing and then cooling to a temperature lower than the glass transition temperature of the thermoplastic resin and simultaneously releasing the sealing of the bag material is shown. When the preform is cooled in a state of being in close contact with the shaping mold, the shaping mold shrinks due to the coefficient of linear expansion, so the preform also shrinks, and there is a problem that wrinkles occur. It is possible to produce a preform that suppresses the generation of wrinkles and is excellent in quality.

However, Patent Document 2 does not show a method for transporting and arranging the preform in the mold, and even if a preform having a good quality can be manufactured, the preform is molded as described above. When transported to a mold, there is a problem that the preform is deformed, and it is difficult to accurately place the preform on the mold, so that a fiber-reinforced plastic member having a good quality cannot be molded. In particular, since recent structural members for aircraft have a large shape and a complicated shape, it has been required to place a preform with high positional accuracy on a mold having a complicated shape.
Japanese Patent Laid-Open No. 2007-1298 JP 2008-6814 A

  In view of such problems, the problem of the present invention is that the conveyance jig itself is adhered and conveyed through the resin material that the preform base material has, so that it is excellent in handleability and ease of conveyance, and the preform is applied. Providing a preform transport method that can be transported to a molding die while maintaining its shape and without deteriorating the quality of the preform, and can be accurately placed at the same position every time at a predetermined position on the molding die. It is to be.

The present invention employs the following means in order to solve such problems. That is,
(1) A state in which a preform having a resin material mainly composed of a thermoplastic resin and / or a thermosetting resin on the surface of a reinforcing fiber substrate is temporarily bonded to a preform conveying jig via the resin material. A method for producing a fiber-reinforced plastic, comprising: a step of removing the preform conveying jig from the preform and placing the preform on the molding die after being transferred to the molding die.

  (2) The preform conveying jig has a fitting mechanism that determines the installation position in the mold, and the preform temporarily bonded to the preform conveying jig is installed in the molding die by the fitting mechanism. The manufacturing method of the fiber reinforced plastic as described in (1).

  (3) The method for producing a fiber-reinforced plastic according to (2), wherein the fitting mechanism is a pin and a pin hole.

  (4) The method for producing a fiber-reinforced plastic according to (2), wherein the fitting mechanism is a key and a groove.

  (5) The method for producing a fiber-reinforced plastic according to any one of (1) to (4), wherein the preform conveying jig has a rotation mechanism capable of rotating the preform.

  (6) The method for producing a fiber-reinforced plastic according to any one of (1) to (5), wherein temporary adhesion between the preform conveying jig and the preform is performed by heating.

  (7) The method for producing a fiber-reinforced plastic according to any one of (1) to (6), wherein a temporary bonding portion between the preform and the preform conveying jig is intermittent.

  (8) A preform conveying jig is preliminarily mounted on a shaping mold for producing a preform, and at the same time as the preform is produced, the preform conveying jig is temporarily bonded to the preform. (7) The manufacturing method of the fiber reinforced plastic in any one of.

  (9) The method for producing a fiber-reinforced plastic according to any one of (1) to (8), wherein a part or all of the shaping mold constitutes a preform conveying jig.

  (10) The method for producing a fiber-reinforced plastic according to any one of (1) to (9), wherein the preform conveying jig has an opening for injecting resin into the mold.

  According to the present invention, it is possible to easily convey a preform to a mold while maintaining a predetermined shaping shape. At the same time, the fiber reinforced plastic with high reproducibility and reliability can be obtained because it can be accurately placed at a predetermined position of the mold at the same position every time. In particular, a long-shaped preform that is easily deformed by its own weight or the like can be transported and placed in a mold without deformation and with high positional accuracy. In addition, operations such as correction of the deformed preform and adjustment of the placement on the mold are not required, so that it is possible to manufacture with high productivity.

  Below, this invention is demonstrated based on one embodiment shown in FIGS. In addition, this invention is not limited to the aspect described in the said drawing.

  A preferred shaping mold 1 used in the present invention is equipped with a conveying jig 2 as shown in FIG. A conveying jig 2 is preliminarily equipped on a part or the whole of the shaping mold 1, and the conveying jig 2 can be easily detached from the shaping mold 1. The material of the shaping mold 1 and the conveying jig 2 is made of metal, resin, FRP, wood, etc., and a part or the whole of the conveying jig 2 (the surface of the conveying jig 2 in FIG. 1) is a preform 3 at the same time. It has the shape of The shaped shape has a shape required as a preform 3 of the fiber reinforced plastic to be manufactured. With the shaping die 1 equipped with a conveying jig 2, a thermoplastic resin is formed on the surface thereof. A preform 3 is manufactured by laminating and shaping a fiber reinforced base material having a resin material as a main component.

  As will be described later, the forming is performed by pressing or depressurizing the fiber reinforced base material, and the shaping force acts on the surface of the conveying jig 2 having the shaping shape. A structure and fixing method in which the tool 2 is not damaged, misaligned, separated or the like are preferable. In order to be able to attach to and remove from the shaping mold 1 later, this fixing method is pin-fixed (structure that is fixed with pins and pin holes), key-fixed (structure that is fixed with keys and grooves), and screwed (fixed with male and female screws). Structure) is preferred, and this fixing means is in a portion other than the surface having the required shaping shape.

  The preferred fiber reinforced substrate of the present invention is a continuous fiber or a discontinuous material such as glass fiber, alumina fiber, silicon carbide fiber, metal fiber, organic (polyaramid, PBO, liquid crystal polymer, PVA, PE, PPS, etc.) fiber or carbon fiber. It has a cloth shape such as woven fabric, non-woven fabric, and mat made of fiber. In particular, carbon fibers are preferably used as reinforcing fibers for structural members such as aircraft and automobiles because they are excellent in specific strength, specific elastic modulus, water absorption and the like.

  By having a resin material on the surface of each fiber reinforced base material, it is possible to improve the mechanical properties by improving the toughness of the laminated interlayer part of the molded product, and to stabilize the shape of the preform by heat fusion during lamination on the mold At the same time, temporary adhesion by thermal fusion with the conveying jig 1 of the present invention is possible, and stabilization during preform conveyance can be achieved, which is preferable. Examples of the resin material include thermoplastic resins and thermosetting resins, which 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, and strong polymerization resins. Among them, it is preferable to use polyimide, polyetherimide, polyphenylene ether, or polyethersulfone, because the strength between sheets can be increased.

  As the thermosetting resin, an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a phenol resin, or 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 the thermoplastic resin with a thermosetting resin, the solvent resistance of the thermoplastic resin is improved by the thermosetting resin, and a high toughness improving effect peculiar to the thermoplastic resin is obtained. It becomes possible. For such purposes, the blending amount of the thermoplastic resin in the resin material is preferably 30 to 100% by weight from the viewpoint of obtaining a fiber reinforced plastic excellent in impact resistance.

  Preferable forms of the resin material include, for example, particles, fibers, and films. Among them, the form of the particles is preferable from the viewpoint that the types of resins that can be used are various and the fiber-reinforced volume ratio in the preform 3 can be increased. The smaller the average diameter, the more uniformly the particles can be dispersed on the reinforcing fiber substrate. Therefore, the diameter is preferably 1 mm or less, more preferably 250 μm or less, and even more preferably 50 μm or less. The average thickness of the particles on the surface of the reinforcing fiber base is preferably 5 to 250 μm.

Adhesion amount of the resin material, the effect of the characteristics as described above can be obtained, and preferably from 2 to 40 g / m ² from the viewpoint of not inhibiting the impregnation of the matrix resin, more preferably at 10~35g / m ² . In addition, the adhesion surface of this resin material is not specified as either one surface or both surfaces as long as impregnation property and FRP mechanical properties are not hindered. More preferably, double-sided adhesion is used.

  A preferred embodiment of the preform 3 to be transported by the transport jig 2 of the present invention is prepared by laminating 1 to 100 reinforcing fiber bases. It is obtained by placing on the shaping mold 1 in which the conveying jig 2 is incorporated by the fixing method and heating and shaping to a temperature higher than the glass transition temperature of the resin material in a slightly pressurized state. The method of pressurizing the laminate may be either positive pressure from the outside or pressurization using atmospheric pressure by bagging the laminate and making the bag interior negative pressure. In this heating shaping, the resin material is also thermally fused to the conveyance jig 2 to provide conveyance stability of the preform 3 by the conveyance jig 2.

  The transfer jig 2 does not need to be subjected to a mold release process or a release cloth in order to provide adhesion of the preform 3, but the transfer jig 2 and the preform after transfer are not required. In order to improve the releasability with respect to 3, it is preferable to discontinue or disperse and dispose the release cloth or dispose the release cloth (see the circled portion in FIG. 4). And the temporary bonding location between the preform 3 and the preform 3 are intermittent. In addition, it is preferable that this mold release process or arrangement | positioning of a mold release cloth shall be 10 to 90% with respect to the area of the shaping surface of the conveyance jig 2, More preferably, it is 30 to 50%. On the other hand, it is preferable that the shaping mold 1 can be removed from the shaping mold 1 by performing a mold release treatment or disposing a release cloth on the entire surface.

  The conveying jig 2 may use the shaping die itself as a conveying jig. However, by making the conveying jig 2 a part of the shaping die 1, functions such as improving workability during conveyance are provided. It can be given and is preferable. The preform 3 shaped on the shaping mold 1 and the conveying jig 2 and thermally fused with the resin material is transferred together with the conveying jig 2 to the molding die. Since the preform 3 is moved in a state of being heat-sealed to the conveying jig 2, it is possible to manufacture a member that is reproducible and highly reliable with no deformation or deformation of the preform during conveyance. It becomes possible.

  The transport jig 2 is separated from the shaping mold 1 and moved to the molding mold 4. If the weight of the transport jig 2 and the preform 3 is light, the transport jig 2 can be moved by hand or robot, but the crane, air You may perform conveyance by attraction or magnetic force.

  When the preform 3 is transferred to the molding die 4, the preform 3 and the molding die 4 are aligned with good reproducibility, so that the shaping die 1 is fixed to the conveying jig 2 described above. It is preferable to have a structure for fixing the conveying jig 2 using a pin structure (for pinning), a keyway (for keying), a fitting mechanism (for screwing), etc. . Thereby, the prepared preform 3 and the mold 4 are always matched, and it becomes possible to manufacture a highly reliable structural member without creating defects such as a resin-rich portion during molding. The conveying jig 2 may be molded while being mounted on the molding die 4, but from the workability when the conveying jig is removed after molding, the preform 3 is detached from the preform 3 after the preform 3 is placed on the molding die 4. It is preferable to do this.

  The transfer jig 2 is provided with a rotation mechanism as shown in 5 of FIG. 3 so that it can be transferred from the male shaping die 1 to the female die 4. This is preferable because there is no load such as twisting of the preform.

  It is also a preferred embodiment to have a structure for injecting resin into the conveying jig 2. Specifically, the transfer jig 2 is provided with a groove or hole for injection of resin, so that the preform is transferred to the molding die 4 together with the transfer jig 2, and then the process proceeds to the resin injection process. By being able to do so, there are effects such as improvement in workability and reduction in manufacturing time. At this time, it is preferable to open a large number of hole-like openings from the point of uniform dispersion of the resin and the removal point of the conveying jig 2 after molding. The size of the hole-shaped opening is preferably 0.1 to 2 mm in order to efficiently impregnate the injected resin into the preform and maintain the surface shape of the molded product. The shape of the opening is preferably a circular shape from the viewpoint of ease of processing, but may be a square shape or a triangular shape.

  The preform transferred onto the mold 4 is injected and impregnated with a resin by a molding method such as the RTM method or the VaRTM method, and the resin is cured to obtain a molded product made of fiber reinforced plastic.

  The present invention is particularly suitable when the cross-sectional shape as shown in FIG. 1 is a member having an irregular cross-sectional shape such as a C-type, and the dimensional accuracy and surface smoothness of the outer shape of the C-type member are required. Can be used for In order to shape a laminate of reinforcing fiber bases into a C-shaped cross-sectional shape, by using a male shaping die 1 as shown in FIG. The shape 6 is preferable because it can be formed with good quality. On the other hand, when this male shaping mold is used as molding, the dimension of the outer shape of the C-shaped member varies depending on the thickness change of the member, so that the dimensional accuracy of the outer shape is lowered and the surface smoothness is also lowered. It is preferable to convey and arrange in a female mold 4 for molding. In this case, it is necessary to transport and arrange the preform having a modified cross-sectional shape produced by the male shaping die 1 to the female molding die 4 without impairing the quality, so that the present invention is preferably used. It can be done.

Example 1
As a result of manufacturing an aircraft member having a C-shaped dimension of about 300 mm in length, 300 mm in width, and 6000 mm in length using the shaping mold 1, the shaping mold 4, and the conveying jig 2 as shown in FIGS. A good and stable fiber-reinforced plastic member could be obtained.

The reinforced fiber substrate used was a woven fabric sheet having a carbon fiber weight of 190 g / m ² using carbon fibers having a tensile strength of 5800 MPa and a tensile modulus of 290 GPa and 24,000 filaments. In the process of weaving the woven sheet, a resin material powder obtained by pulverizing a mixed resin having a mixture ratio of polyethersulfone and epoxy resin of 60:40 was sprayed on the woven sheet and heat-sealed. In addition, the adhesion amount of this resin material to the woven fabric sheet was 27 g / m ² . After laminating the reinforcing fiber substrate up to 16 to 48 ply on the upper part of the tool plate, the laminate was temporarily bonded using a thermocompression bonding jig to produce a laminate for preform.

  This preform laminated body was arrange | positioned on the shaping apparatus which attached the conveyance jig 2 to the shaping type | mold 1 by pinning as shown in a figure. At this time, the mold release process was intermittently performed on the shaping surface of the conveying jig 2. The preform 3 placed on this shaping apparatus was vacuum-shaped with a rubber bag, and a shaping operation was performed at 80 ° C. for 2 hours by a heating device built in the shaping mold 1. After the shaping is completed, the conveying jig 2 is removed from the shaping mold 1, the conveying jig 2 is lifted together with the preform 3, and conveyed to the forming mold 4. As a result, the preform is detached from the conveying jig, displaced, or twisted. It could be transported without any occurrence.

  The transported preform is reversed by the rotation mechanism 5 equipped on the transport jig 2, fitted into the molding die 4, and the molding die 4 and the transport jig 2 are aligned with pins. I was able to put the preform in the proper position. After the mounting, the conveying jig could be easily detached from the preform 3, and the preform 3 could be detached from the molding die 4 due to the separation and the preform 3 on the separation surface was not damaged.

  Then, resin injection hardening was implemented to this preform 3 by VaRTM method, and shaping | molding was implemented. Since the preform 3 and the mold 4 matched, it was possible to produce a good fiber-reinforced plastic molded article without defects such as resin richness.

(Comparative Example 1)
A mold release process was performed on the entire shaping surface of the conveying jig 2, and a preform was prepared in the same manner as in Example 1 except for that. When the transport jig 2 was fixed to the shaping mold 1 and only the preform 3 was detached and transported to the forming mold 4, the preform 3 was deformed during transport. Further, when the preform 3 was visually aligned with the molding die 4 and molded, a resin-rich defect due to a slight deviation between the preform 3 and the molding die 4 occurred.

(Example 2)
A circular hole with a hole diameter of 1 mm is processed at a pitch of 1 mm in the conveying jig 2, a release cloth is arranged on the front surface of the conveying jig 2, and the arrangement to the forming die 4 is performed in the same manner as in Example 1. While the conveying jig 2 was adhered to the preform 3, the round hole was used as a resin injection hole for molding. The resin is impregnated into the preform 3 without any problem, and the release of the conveying jig 2 from the molded product after curing can be performed well through the release cloth. The molded product could be manufactured with good reproducibility.

This figure is a perspective view in which a preform is produced on a shaping mold on which a conveying jig is installed. This figure is a perspective view in which the preform temporarily bonded to the conveying jig is detached from the shaping mold. This figure is a perspective view of a state where the preform temporarily bonded to the conveying jig is inverted using a rotation mechanism. This figure is a plan view of the reversed conveying jig and preform. The ◯ part of the broken line indicates the part not yet processed. This figure is a plan view in which an inverted conveying jig and a preform are installed in a mold. This figure is a plan view showing a state where the conveying jig is removed from the installed preform.

Explanation of symbols

1 Forming mold 2 Transfer jig (Preform transfer jig)
3 Preform 4 Mold 5 Rotation mechanism 6 Corner R shape

Claims (10)

Mold with a preform having a resin material mainly composed of a thermoplastic resin and / or a thermosetting resin on the surface of a reinforcing fiber base material, and temporarily bonded to a preform conveying jig via the resin material A method for producing a fiber reinforced plastic, comprising: a step of removing the preform conveying jig from the preform and placing the preform on a molding die after being conveyed and installed. The preform conveying jig has a fitting mechanism for determining an installation position on the molding die, and the preform temporarily bonded to the preform conveying jig is installed in the molding die by the fitting mechanism. 2. A method for producing a fiber reinforced plastic according to 1. The manufacturing method of the fiber reinforced plastics of Claim 2 whose fitting mechanism is a pin and a pin hole. The manufacturing method of the fiber reinforced plastics of Claim 2 whose fitting mechanism is a key and a groove | channel. The method for producing a fiber-reinforced plastic according to any one of claims 1 to 4, wherein the preform conveying jig has a rotation mechanism capable of rotating the preform. The manufacturing method of the fiber reinforced plastics in any one of Claims 1-5 which performs temporary adhesion | attachment with a preform conveyance jig and preform by heating. The manufacturing method of the fiber reinforced plastics in any one of Claims 1-6 whose temporary adhesion location of a preform and a preform conveyance jig | tool is intermittent. The preform conveying jig is preliminarily mounted on a shaping mold for producing a preform, and the preform conveying jig is temporarily bonded to the preform at the same time as the preform is produced. A method for producing the fiber-reinforced plastic according to claim 1. The manufacturing method of the fiber reinforced plastics in any one of Claims 1-8 in which a part or all of a shaping type | mold comprises the preform conveyance jig. The manufacturing method of the fiber reinforced plastics in any one of Claims 1-9 which has an opening part which inject | pours resin into a shaping | molding die in a preform conveyance jig | tool.

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