JP2014188953A - Preforming body and production method of the same, and fiber-reinforced resin molding using the same and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preforming body and a fiber-reinforced resin molding in which an easy mold and a core material are used for producing them, and a fiber orientation is maintained while retaining Vf evenly for enlarging size, and which can be produced by smaller numbers of processes compared with conventional ones, in producing a fiber-reinforced resin molding to which load other than pulling such as flexure, twisting, compression, and shear is applied and a fiber-reinforced resin molding having a complicated shape.SOLUTION: Provided is the preforming body produced by laminating a fiber-reinforced cloth 20 on an outer peripheral face of a core body 10 which is formed into a predetermined shape. A heat shrinkable tube 30 coats an outer periphery of the fiber-reinforced cloth 20 and the fiber-reinforced cloth 20 is fixed on the outer peripheral face of the core body 10 by performing heating.

Description

  The present invention relates to a fiber reinforced resin molded article obtained by an RTM (Resin Transfer Molding) molding method, and more specifically, after molding a preform using a core body, impregnating and curing the resin. The present invention relates to a fiber-reinforced resin molded product to be obtained.

  CFRP (Carbon Fiber Reinforced Plastic) and GFRP (Glass Fiber Reinforced Plastic) using carbon fiber and glass fiber as reinforcing fibers have high strength, high rigidity, light weight, and high durability. It is an ideal material as various structural materials for aircraft, bicycles and the like.

  As a structural material using CFRP or GFRP, various methods for economically producing a beam material such as a beam or a column, a pipe material used for a frame structure, a monocoque structural material whose outer skin is subjected to stress, and the like have been studied.

  As a method for producing a structural material by molding these CFRP and GFRP, for example, a laminate made of reinforced fibers and high-toughness epoxy resin, in which prepregs having a thickness of several tens to several hundreds of micrometers are stacked one by one. A so-called autoclave molding method is generally used in which pressure is set by heating and curing in an autoclave.

  However, since the prepreg is generally impregnated with a resin around the reinforcing fiber, the reinforcing fiber is fixed with the resin, and the prepreg is shaped into a predetermined three-dimensional structure. It was difficult to deform.

  For this reason, when manufacturing FRP aircraft members, automobile members, and bicycle members having a three-dimensional shape with unevenness, a manufacturing method in which prepreg is cut even for unevenness of several millimeters and joined in a patch shape. For this reason, a member made of a prepreg is not only heavier than expected, but also requires a greater safety factor due to a decrease in strength of the joint portion.

  For these reasons, the application of FRP to aircraft members and automobile members has been promoted with respect to those having a relatively flat shape, and there has been a restriction that application to complicated shape members is limited.

  Furthermore, when prepregs are stacked and stuck one by one in the prepreg, if air enters between the layers of the prepreg, these bubbles will not disappear even by pressurization with an autoclave, and voids will be formed inside the FRP. Had a problem that would become a serious defect in strength. For this reason, several prepregs are stacked, wrapped in a bag film, evacuated, and pre-treatment is required to release air in advance.

  As a method for producing CFRP and GFRP that solves such problems in prepreg molding, a molding method called an RTM molding method as described in US Pat. No. 5,281,388 has attracted attention. For example, An FRP structure having a length of 10 m or more and a complicated shape is being put into practical use by this method.

  According to this RTM molding method, the process for producing CFRP and GFRP is a so-called preformed body (also referred to as a preform), which has been previously shaped into a predetermined shape and is not completely impregnated with a resin. After placing the reinforcing fiber base made of dry continuous fiber fabric on the mold and covering the whole with a bag film or mold, the bag film or the mold mold is evacuated, and the resin is injected, The preform is diffused and impregnated with resin.

  In the RTM molding method, since the preform is used as described above, a complicated process of cutting a sticky material called a prepreg and attaching it in a patch shape becomes unnecessary. However, it is RTM molding how to accurately and efficiently perform the process of manufacturing a preform by forming a one-dimensional or two-dimensional reinforcing fiber substrate such as a fiber or fabric into a predetermined three-dimensional shape. It is also an issue in the law.

  The simplest conventional method of this shaping process is to manually cut a reinforcing fiber substrate such as cloth, and apply spray paste etc. one by one on the shaping mold that conforms to the shape of the final product. There is a method of applying multiple layers while spraying.

  In such a manual method, first, regarding the point of laminating the reinforcing fiber base material one by one, the use of a dry base material is better along the mold than the prepreg, and the pasting work is easy. Although there is a significant improvement in efficiency. In addition, regarding the pasting work by spraying, it is difficult to control the spraying amount, and there is a concern that the physical properties of the FRP itself may be deteriorated or varied due to excessive coating or variation in the coating amount.

  When a high bulk Vf (also referred to as fiber volume content) preform is produced in the molding process of the RTM molding method, the preform swells from the specified height due to repulsion of the internal reinforcing fibers, and does not fit in the mold. It may disappear. In the case of a complex-shaped preform, the internal reinforcing fibers may jump out of the preform without following the shape. When such a state occurs, the reinforcing fibers are cut in the mold clamping process of the molding die, or the reinforcing fibers are undulated by forcibly clamping the mold. Cutting or waviness of the reinforcing fiber causes a decrease in the physical properties of the fiber-reinforced resin molded product.

  When manufacturing plate materials and girders by FRP, the deterioration of physical properties of the fiber reinforced resin molded product due to the cutting or beat of the reinforcing fibers is fatal to the structural material. Manufacture and remove the part where physical properties may be lowered to make a product.

  On the other hand, in the preform having a cylindrical structure, when the reinforcing fibers in the preform are arranged so as to straddle the mating surfaces of the pair of molds, the reinforcing fibers are sandwiched or swelled between the mating surfaces of the molds. In such a case, it is impossible to perform the step of removing the portion where the physical property deterioration described above occurs. If the reinforcing fiber is cut by the molding die, the physical properties of the molded product may be significantly reduced.

  Furthermore, when a cylindrical preform is used as a structural material, a high fiber volume content (Vf), fiber continuity guarantee, fiber orientation guarantee, etc. can be achieved. If it is going to realize performance and high precision at the same time, it becomes difficult to shape the reinforcing fiber base as expected, and as a result, it is difficult to stably maintain the form of the preform. As described above, there are still many problems in the formation of a preshaped object having a complicated shape.

  As a method for manufacturing a cylindrical structure preform from a reinforcing fiber base material, for example, in Patent Document 1, reinforcing fibers are aligned and laminated in a certain direction on the outer peripheral surface of a core body, and fiber yarns having high heat shrinkability are used. By wrapping the whole with the configured net-like bag, secondarily temporarily fixing the required portion with the same fiber thread from the top of the net-shaped bag, and heating the molded body thus configured at a predetermined temperature by placing it in an oven A method for shrinking a heat-shrinkable net-like bag is disclosed. However, the invention described in Patent Document 1 requires a primary temporary fixing process, a net-shaped bag covering process, and a secondary temporary fixing process in the manufacturing process of the preform. It takes time.

  Also, since a unidirectional reinforcing fiber base material is used, the tensile strength and rigidity of the fiber reinforced resin molded product are exhibited in the direction in which the fibers are oriented, but bending, twisting, compression, shearing in the direction in which the fibers are not oriented The strength / rigidity may be significantly reduced compared to the fiber orientation direction.

  Furthermore, since a net-like bag is used to maintain the shape, for example, when applied to a complex-shaped core such as a brake assembly part of a bicycle frame, it cannot follow the shape change of the core smaller than the net of the net, and the mold is closed. Occasionally, the reinforcing fiber is cut by sandwiching the preform, or the area for transmitting the pressure from the outside due to shrinkage to the unidirectional reinforcing fiber base is reduced, and it has a problem that it is difficult to increase or uniformize Vf. .

  Furthermore, when the matrix resin is injected from the outer peripheral surface, the fiber orientation in the unidirectional reinforcing fiber base material is disturbed by the injection pressure and flow rate of the matrix resin, which may result in a molded product with non-uniform strength and rigidity.

JP 7-24920 A

  The present invention has been devised by paying attention to such a problem, and produces a fiber reinforced resin molded product that is subjected to a load other than tension such as bending, twisting, compression, and shearing, and a fiber reinforced resin molded product having a complicated shape. In this case, a preform that can be shaped while keeping the fiber orientation uniform while maintaining the fiber orientation, and its manufacturing method, and its preform are used in fewer steps than in the past. An object of the present invention is to provide a fiber-reinforced resin molded product.

The present invention can be achieved by the following (1) to (14).
(1) In a preform formed by laminating the reinforcing fiber fabric 20 on the outer peripheral surface of the core body 10 formed into a predetermined shape, the outer periphery of the reinforcing fiber cloth 20 is covered with a heat shrinkable tube 30, and the core is heated by heating. A preform formed by fixing the reinforcing fiber fabric 20 to the outer peripheral surface of the body 10.
(2) The preform according to (1), wherein a plurality of the heat-shrinkable tubes 30 are arranged at intervals in the axial direction of the core body 10.
(3) The preform according to (1) or (2), wherein at least one resin injection / discharge hole is provided on the outer peripheral surface of the heat shrinkable tube 30.
(4) The preform according to any one of (1) to (3), wherein a design is applied to the surface of the heat shrinkable tube 30.
(5) The preformed body according to any one of (1) to (4), wherein the reinforcing fiber fabric 20 includes at least one of a woven fabric, a knitted fabric, a nonwoven fabric, and a unidirectional substrate.
(6) The preform according to any one of (1) to (5), wherein the reinforcing fiber fabric 20 has thermoplastic resin particles attached to a surface thereof.
(7) The preform 10 according to any one of (1) to (6), wherein the core body 10 is a bag-like body that can be pressurized and expanded.
(8) The preform according to any one of (1) to (7), wherein the core body 10 is soluble.
(9) A fiber-reinforced resin molded product obtained by RTM molding of the preform according to any one of (1) to (8).
(10) A fiber-reinforced resin molded article, wherein the heat shrinkable tube 30 is removed from the preform according to any one of (1) to (8) before RTM molding.
(11) In the method for manufacturing a preform, in which the reinforcing fiber fabric 20 is laminated on the outer peripheral surface of the core body 10 molded into a predetermined shape, the following molding steps (A) and (B) are included. Body manufacturing method.
(A) Step: A covering step of laminating one or a plurality of the reinforcing fiber fabrics 20 on the outer peripheral surface of the core body 10 formed into a predetermined shape, and further covering the heat shrinkable tube 30 on the outer periphery.
(B) Step: A fixing step in which the heat-shrinkable tube 30 is contracted by heating and the reinforcing fiber fabric 20 is fixed to the outer peripheral surface of the core body 10.
(12) In the manufacturing method of the fiber reinforced resin molded article which performs RTM molding of the preform obtained by the manufacturing method of the preform according to (11), the following steps (C) to (F) are included. A method for producing a fiber-reinforced resin molded product.
(C) Process: A mold clamping process in which the preform is placed on a mold and clamped.
(D) Process: A curing process in which a matrix resin is injected, impregnated, and cured.
(E) Process: Demolding process of demolding the fiber reinforced resin molded product from the mold.
(F) Process: The trim process which removes the burr | flash etc. of a fiber reinforced resin molded product.
(13) The method for producing a fiber-reinforced resin molded article according to (12), further including a removing step of removing the heat shrinkable tube 30 before the (C) mold clamping step.
(14) In the step (A), the soluble core body 10 or the pressure-expandable bag-shaped core body 10 is selected, and after the curing step (D), the core body 10 is melted or broken, and the core The method for producing a hollow fiber reinforced resin molded article according to (12) or (13), further comprising a removing step of removing the body 10 from the fiber reinforced resin molded article.

  According to the present invention, in producing a fiber reinforced resin molded product that is subjected to a load other than tension such as bending, twisting, compression, and shearing, and a fiber reinforced resin molded product having a complicated shape, the number of man-hours can be reduced and the number of man-hours can be reduced. Pre-molded body that can be shaped while maintaining fiber orientation while maintaining fiber orientation and a manufacturing method thereof, and a fiber-reinforced resin molded article using the preform and a manufacturing method thereof Can be provided.

It is explanatory drawing of the shaping process which shapes a preforming body using the core in this invention. It is explanatory drawing of the shaping | molding process which shape | molds a fiber reinforced resin molded object using the preforming body in this invention.

  Hereinafter, an embodiment of the preform of the present invention and a manufacturing method thereof, and a fiber-reinforced resin molded product and a manufacturing method thereof will be described with reference to the drawings. The present invention is not limited to these drawings.

  Fig.1 (a) is the schematic of the core which concerns on this invention. The core body 10 is used as a core material for accurately molding the fiber-reinforced resin molded body obtained by the present invention, particularly a cylindrical fiber-reinforced resin molded body having a complicated shape. The core 10 is preferably pressed from the outside by a heat-shrinkable tube 30 to be described later. Further, since a resin injection pressure is applied at the time of resin injection, a material having hardness that does not cause excessive deformation due to such external pressure is preferable. .

  Although the material of the core body 10 is not particularly limited, for example, when embedded in a molded product, a material having a light specific gravity such as a foam material or a pressure-expandable bag-like body is preferable. It is preferable to use a pressure-expandable bag or a resin mixed with glass beads.

  On the other hand, in order to be able to extract from a molded product, for example, a pressure-expandable bag-like body can be suitably used. The bag-like body may follow the internal pressure by injecting compressed gas or the like in accordance with the action of the external pressure. Further, when the core body 10 is dissolved and removed from the molded product, it is preferable to select a soluble member, for example, foamed hard urethane, as a raw material, and to melt and take it out in methyl ethyl ketone. Moreover, the bag-like body which can be pressurized and expanded can be pulled out after the internal gas is extracted or cut.

  The reinforcing fiber fabric 20 is not particularly limited, but it is preferable to use at least one of a woven fabric, a knitted fabric, a nonwoven fabric, and a unidirectional substrate. As the reinforcing fiber to be used, for example, carbon fiber, glass fiber, aramid fiber, Kevlar fiber and the like are preferably used. In addition, the reinforcing fiber fabric 20 needs to satisfy the fiber orientation and the fiber amount specified by the design. By using the reinforcing fiber fabric 20 according to the design, strength and rigidity along the fiber orientation can be expressed.

  One or more reinforcing fiber fabrics 20 are arranged on the outer periphery of the core body 10. The sheet-like reinforcing fiber fabric 20 may be wound around the core body 10, or the reinforcing fiber fabric 20 formed in a cylindrical shape in advance may be disposed so as to cover the core body 10. At this time, it is preferable that the reinforcing fibers are oriented in the circumferential direction of a fiber reinforced resin molded article obtained by resin impregnation described later, because strength and rigidity in the circumferential direction can be expressed highly.

It is also preferable to attach the thermoplastic resin particles to the reinforcing fiber fabric 20 in order to increase the stability of the preform. The thermoplastic resin particles applied to the surface of the reinforcing fiber fabric may be applied only to one surface of the reinforcing fiber fabric, or may be applied to both the front and back surfaces. Although enhanced application amount of the surface of the fiber fabric 20 is not particularly limited, in order to take advantage of the thermoplastic resin particles as a binder for heat fusing, thereby the per side 3g / m ² 50g / m ² is applied It is preferable that the range of 5 g / m ² to 30 g / m ² is suitably applied in consideration of a sufficient adhering force to the mounting surface and a balance of weight reduction.

  The thermoplastic resin that is the main component of the thermoplastic resin particles is not particularly limited, but polyimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyamide resin, polyamideimide resin, polyarylene oxide resin Resins belonging to so-called engineering plastics such as polyether ketone resins and polyether ether sulfone resins are preferably used. In addition to this, it may be partially crystalline, and these are also preferably used. For example, poniphenylene sulfide resin, polyether ether ketone resin, polyester resin, nylon resin and the like can be mentioned. Moreover, it is preferable that this thermoplastic resin has a functional group (specifically, carboxyl group, amino group, phenolic hydroxyl group, epoxy group, etc.) capable of reacting with the liquid epoxy resin composition at the terminal or side chain. By having a reactive functional group, it is cured together with the liquid epoxy resin composition, and the impact resistance of the fiber-reinforced composite material is improved. Moreover, arbitrary components other than those described above, for example, antioxidants, rubber particles, inorganic particles, and the like can be appropriately included.

  The thermoplastic resin particles preferably have a glass transition temperature of 50 ° C. or higher. If it is less than 50 degreeC, there exists a possibility that it may become difficult to maintain a thermoplastic resin particle-like composition during storage.

  The thermoplastic resin particles preferably have an average particle size of 30 to 200 μm. By making the average particle diameter 30 μm or more, when manufacturing the reinforcing fiber base material, the particles do not excessively enter the reinforcing fiber yarn of the reinforcing fiber fabric, and a sufficient amount of particles are also present on the surface of the reinforcing fiber yarn. The effect of binding the reinforcing fiber bases can be efficiently expressed even with a small amount of the binder composition, and handling can be facilitated. On the other hand, by setting the average particle size to 200 μm or less, it is possible to prevent waviness when the preform is formed and adversely affect the physical properties of the fiber reinforced plastic.

  The heat shrinkable tube 30 is not particularly limited, but a tube having a heat shrinkage of 10% or more is preferable. For example, a material made of a material that shrinks when heated at about 40 ° C. to 150 ° C. is preferable. For example, when embedding in a molded article, it is preferable to use polyolefin, polyvinyl chloride, or the like. On the other hand, when removing from a molded article, it is preferable to use polyvinylidene fluoride or the like.

  In order to improve the resin impregnation property, a plurality of the heat-shrinkable tubes 30 may be present in the axial direction with a space therebetween, or may have at least one hole on the outer peripheral surface as a resin injection hole. By arranging a plurality of heat-shrinkable tubes 30 in the axial direction or providing resin injection holes in the heat-shrinkable tubes 30, it can act as a resin diffusion medium. Specifically, the resin diffuses through the gap between the heat shrinkable tube 30 and the mold, and the reinforcing fiber fabric can be impregnated with the resin from the resin injection hole or the gap between the heat shrinkable tubes 30. Alternatively, the resin can be uniformly impregnated even for a molded product having a large or complicated shape.

  Furthermore, when embedding the heat-shrinkable tube 30 inside the molded product, a design may be applied to the surface of the heat-shrinkable tube 30. Since the design surface is embedded in the resin, the painting process can be omitted and the design surface is strongly protected. RTM molding is known to have a better surface quality compared to prepreg molding, and the surface smoothing step can be omitted. A transparent heat-shrinkable tube 30 may be used for the purpose of utilizing fiber orientation as a design or confirming fiber orientation.

The method for producing a preform according to the present invention includes the following steps (A) and (B).
(A) Step: A covering step of laminating one or a plurality of the reinforcing fiber fabrics 20 on the outer peripheral surface of the core body 10 formed into a predetermined shape, and further covering the heat shrinkable tube 30 on the outer periphery.
(B) Step: A fixing step in which the heat-shrinkable tube 30 is contracted by heating and the reinforcing fiber fabric 20 is fixed to the outer peripheral surface of the core body 10.

  (A) In the covering step, “predetermined shape” means that the gap amount between the core body 10 and the mold is the thickness of the heat shrinkable tube 30 and the Vf (fiber deposition content) of the reinforcing fiber fabric 20 is 50% to 60. It is preferable to have a shape that results in a thickness amount that is a sum of thicknesses that are%.

  Here, in consideration of the load applied to the fiber-reinforced resin molded article, it is preferable to arrange the fiber amount and the fiber orientation sufficient to express the desired strength and rigidity. The fiber amount and fiber orientation can be obtained by designing such as strength calculation.

  When one or more reinforcing fiber fabrics 20 are laminated on the core 10 and the ends of the reinforcing fiber fabric 20 are frayed, temporarily tighten the ends using a masking tape, spray glue, string, etc. May be. The fiber orientation can be maintained by the end stop. This temporary fix may be RTM molded as it is and embedded in the product, but it is preferably removed before RTM molding in order to improve dimensional accuracy and surface design.

  FIGS. 1a) -c) illustrate an embodiment of the (A) coating process. One or more reinforcing fiber fabrics 20 are laminated on the outer peripheral surface of the core body 10 as shown in FIG. 1B on the outer periphery of the core body 10 shown in FIG. At this time, a gap may be provided between the core body 10 and the reinforcing fiber fabric 20. Thereafter, as shown in FIG. 1 c, the outer periphery of the reinforcing fiber fabric 20 is covered with a heat shrinkable tube 30.

  FIG. 1 d) illustrates an embodiment of the fixing step (B). When the heat-shrinkable tube 30 whose wall surface is sheet-like is heated, the heat-shrinkable tube 30 starts to shrink uniformly. When pressure is applied from the outside of the reinforcing fiber fabric 20, when the sheet-like reinforcing fiber fabric is wound, the end of the sheet enters inside, and when the cylindrical reinforcing fiber fabric is wound, the fiber bundle interval is made uniform. By narrowing, it is possible to obtain a preform with a high bulk Vf in which the reinforcing fiber fabric has no wrinkles or undulations and no fiber orientation deviation.

The method for producing a fiber-reinforced resin molded article of the present invention is to perform RTM molding of the preformed product produced by the above-described steps (A) and (B), comprising the following steps (C) to (F).
(C) Process: A mold clamping process in which the preform formed in (1) is placed on a mold and clamped.
(D) Process: A curing process in which a matrix resin is injected, impregnated, and cured.
(E) Process: Demolding process of demolding the fiber reinforced resin molded product from the mold.
(F) Process: The trim process which removes the burr | flash etc. of a fiber reinforced resin molded product.

  (C) One embodiment of the mold clamping process is shown in FIG. (B) Since the core body 10 and the reinforcing fiber cloth 20 are integrated by the fixing step, the reinforcing fiber cloth on the mating surface (so-called parting line) of the molding die at the time of mold clamping, even for a complicated shaped member. Twenty pinchings can be reduced. Not only can the physical properties of the molded product be reduced by cutting the reinforcing fibers with the mold, but also the damage to the mold due to the reinforcing fibers themselves can be reduced.

  FIG. 2 b) shows an embodiment of the (D) curing step. (B) Since the reinforcing fiber fabric 20 is held by the core body 10 by the heat shrinkable tube 30 by the fixing step, the orientation disorder of the reinforcing fiber due to the injection pressure of the injection resin can be reduced, and the physical properties according to the design Can be expressed.

  Next, an embodiment of (E) demolding process is shown in FIG. At this time, when burrs or the like occur in the molded product, the appearance can be adjusted by the (F) trim process. In the present invention, since the sandwiching of the reinforcing fibers at the time of mold clamping in the (C) curing process can be reduced, burrs including the reinforcing fibers generated after molding can be reduced, and the trim process time can be reduced. .

  Moreover, in the preform of this invention, its manufacturing method, a fiber reinforced resin molded product, and its molding method, the following processes can be included.

  Heat shrinkable tube removal step: (B) A removal step of removing the heat shrinkable tube 30 before the mold clamping step after the heat shrinkable tube 30 is thermally contracted in the fixing step.

  In the case where thinness, lightness, surface conductivity and the like are required as specifications for the fiber reinforced resin molded product, it is preferable to remove the heat shrinkable tube 30. When removing the heat-shrinkable tube 30, it is preferable to select a material having good releasability as a material or to apply a release material on the surface. Alternatively, the heat-shrinkable tube 30 can be removed without damaging the reinforcing fibers by inserting a blade shallowly in the fiber direction of the outermost surface of the reinforcing fiber fabric 20 with respect to the heat-shrinkable tube 30 and cutting it open.

  Here, when the reinforced fiber cloth to which the thermoplastic resin particles are adhered is used, the thermoplastic resin particles are also dissolved by the heat when the heat shrinkable tube 30 is thermally contracted, and the overlapping portions of the reinforced fiber cloth are fixed. Can do. This is generally called hot compaction, and the shape of the preform can be stably maintained even after the heat shrinkable tube 30 is removed.

  Core body removing step: When thinness, lightness, etc. are required as specifications for the fiber reinforced resin molded product, it is preferable to remove the core body 10 from the fiber reinforced resin molded product. After selecting a soluble or pressure-expandable bag-like body as the core body 10, (D) after the curing step, the core body 10 is dissolved by a solvent, or the pressure-expandable bag-like body is split and pulled. You can start. In particular, when the core 10 is dissolved with a solvent after the trimming step, the melt of the core 10 is prevented from adhering to the molded product when it is dissolved inside the bag-like body and pulled out together with the bag-like body. I can do it.

  The preformed body manufactured by the above-described manufacturing method can be shaped with fewer man-hours than before and using a simple mold or core while maintaining Vf uniform while maintaining fiber orientation. The shape stability of the preform is also increased, and the reinforcing fiber fabric 20 is protected in the heat shrinkable tube 30, so that the durability when the preform is stored after mass production is also improved.

  The fiber reinforced resin molded product manufactured by the above-described manufacturing method maintains the fiber orientation and increases the shape stability of the preshaped object. Therefore, as designed in advance, a load other than tension such as bending, twisting, compression, and shearing is applied. It can be used as such a strength member. At the time of mold clamping during RTM molding, the presence of the heat-shrinkable tube 30 or even when the heat-shrinkable tube 30 is removed, the reinforcing fiber is cut by the mold due to improved shape stability by the thermoplastic resin particles. Therefore, the physical properties of the molded product can be expressed according to the design.

  The hollow fiber reinforced resin molded product manufactured by the above-described manufacturing method can be used as a strength member to which a load other than tension such as bending, twisting, compression, and shearing is applied according to the design, and can be lightweight. The hollow shape has a feature that the second moment of section is larger than the solid shape, so it is not only suitable for structural applications but also for gas-liquid transport and storage using the internal space. It can also be used for applications.

  The present invention can be used as a strength member to which a load other than tension such as bending, twisting, compression, and shearing is applied according to the design. Moreover, the hollow fiber reinforced resin molded product can be used not only for structural applications but also for applications such as gas-liquid transportation and storage using the internal space. Bicycle members made by RTM molding of carbon fiber fabrics can be applied to members that require strength, such as brake assemblies, automobiles, aircraft, etc., but the scope of application is limited to these. It is not something that can be done.

10: Core body 20: Reinforced fiber fabric 30: Heat shrinkable tube 40: Pre-formed body 51: Upper mold 52: Lower mold 53: Resin injection port 60: Fiber reinforced resin molded product

Claims (14)

In the preform formed by laminating the reinforcing fiber cloth 20 on the outer peripheral surface of the core body 10 formed into a predetermined shape, the outer periphery of the reinforcing fiber cloth 20 is covered with a heat shrinkable tube 30, and the core body 10 is heated by heating. A preformed article obtained by fixing the reinforcing fiber fabric 20 to an outer peripheral surface. The preform according to claim 1, wherein a plurality of the heat-shrinkable tubes 30 are arranged at intervals in the axial direction of the core body 10. The preform according to claim 1 or 2, wherein at least one resin injection / discharge hole is provided on an outer peripheral surface of the heat shrinkable tube (30). The preform according to claim 1, wherein a design is applied to a surface of the heat shrinkable tube 30. The preformed body according to any one of claims 1 to 4, wherein the reinforcing fiber fabric 20 includes at least one of a woven fabric, a knitted fabric, a nonwoven fabric, and a unidirectional substrate. The preformed body according to any one of claims 1 to 5, wherein the reinforcing fiber fabric 20 has thermoplastic resin particles attached to a surface thereof. The preform 10 according to any one of claims 1 to 6, wherein the core body 10 is a bag-like body that can be pressurized and expanded. The preform 10 according to any one of claims 1 to 7, wherein the core 10 is soluble. A fiber-reinforced resin molded product obtained by subjecting the preform according to any one of claims 1 to 8 to RTM molding. A fiber-reinforced resin molded product, wherein the heat shrinkable tube 30 is removed from the preform according to any one of claims 1 to 8 before RTM molding. In the method for manufacturing a preform formed by laminating the reinforcing fiber fabric 20 on the outer peripheral surface of the core body 10 formed into a predetermined shape, the following steps (A) and (B) are included. Method.
(A) Step: A covering step of laminating one or a plurality of the reinforcing fiber fabrics 20 on the outer peripheral surface of the core body 10 formed into a predetermined shape, and further covering the heat shrinkable tube 30 on the outer periphery.
(B) Step: A fixing step in which the heat-shrinkable tube 30 is contracted by heating and the reinforcing fiber fabric 20 is fixed to the outer peripheral surface of the core body 10. 12. A method for producing a fiber-reinforced resin molded article in which the preform obtained by the method for producing a preform according to claim 11 is subjected to RTM molding, the fiber comprising the following steps (C) to (F): Manufacturing method of reinforced resin molded product.
(C) Process: A mold clamping process in which the preform is placed on a mold and clamped.
(D) Process: A curing process in which a matrix resin is injected, impregnated, and cured.
(E) Process: Demolding process of demolding the fiber reinforced resin molded product from the mold.
(F) Process: The trim process which removes the burr | flash etc. of a fiber reinforced resin molded product. (C) The manufacturing method of the fiber reinforced resin molded product according to claim 12, further comprising a removing step of removing the heat shrinkable tube 30 before the mold clamping step. (A) The soluble core body 10 or the pressure-expandable bag-shaped core body 10 is selected in the step (A), and after the (D) curing step, the core body 10 is melted or broken, and the core body 10 is The method for producing a hollow fiber reinforced resin molded article according to claim 12 or 13, further comprising a removing step of removing from the fiber reinforced resin molded article.

Images