Manufacturing method of molded body

Abstract

The present invention relates to a method for producing a molded object by integrally molding a composite material including reinforcing fibers dispersed in in-plane directions and a molding material having higher flowability than the composite material, the method comprising the following steps (1) to (3): (1) a step in which the composite material is fixed to a first mold, which has a cavity having a larger area than the composite material in a plan view, with a plurality of fixing members provided to the first mold; (2) a step in which a second mold is moved toward the composite material fixed to the first mold and the second mold is brought into contact with the composite material; and (3) a step in which the composite material and the molding material are pressed by the first mold and the second mold and integrally molded.

Description

[Technical Field]

[0001] The present invention relates to a method for producing a molded article that is integrally molded from a composite material and an injection molding material that has higher fluidity than the composite material. [Background technology]

[0002] Composite materials that use reinforcing fibers such as carbon fiber and glass fiber as reinforcements have high tensile strength and tensile modulus, and a low coefficient of linear expansion, resulting in excellent dimensional stability. They also have excellent heat resistance, chemical resistance, fatigue resistance, abrasion resistance, electromagnetic wave shielding, and X-ray transparency. For these reasons, composite materials are widely used in a variety of fields, including automobiles, sports and leisure, aerospace, and general industrial applications.

[0003] Meanwhile, a method for manufacturing a molded body integrally from a plurality of different materials has been investigated. For example, Patent Document 1 discloses a mold device in which pins are fitted into pin receiving holes while the peripheral edge of a skin material is pressed and held in place by the pressing surface of a skin material pressing frame and the skin material mounting surface of a lower mold. After molten thermoplastic resin is supplied between the skin material held in the lower mold and the molding surface of the upper mold, clamping begins, causing the molten thermoplastic resin to flow and pressing the skin material by the clamping, stretching it to conform to the mold shape and squeezing it into the mold. At the same time, the peripheral edge of the skin material is pulled toward the inside of the mold while sliding between the pins and pin receiving holes and between the pressing surface and the skin material mounting surface.

[0004] Patent Document 2 discloses the use of a mold for producing a fiber-reinforced thermoplastic resin molded product by press-molding a sheet material in which a discontinuous fiber-reinforced thermoplastic resin layer is laminated on at least a portion of one side of a continuous fiber-reinforced thermoplastic resin layer, the mold having a frame-shaped dam portion on the outer periphery of the cavity that prevents the discontinuous fiber-reinforced thermoplastic resin layer from flowing out of the cavity when the upper and lower molds are closed, while forming a gap that allows the continuous fiber-reinforced thermoplastic resin layer to extend out of the cavity.

[0005] Patent Document 3 discloses that an auxiliary mold that is in close contact with the outer peripheral wall of the lower mold of a stamping mold and can slide up and down is arranged, and when a molten thermoplastic resin between the upper and lower molds of the stamping mold is press-molded to form a substrate and a skin material is pressure-bonded to the substrate, the auxiliary mold prevents the molten material from leaking from between the upper and lower molds.

[0006] Patent Document 4 describes a method for producing an injection-molded product containing multiple sheets at lower cost. In Patent Document 4, multiple resin-impregnated reinforcing member sheets with holes are arranged, a movable mold is moved to clamp the mold, and resin is injected to fill the spaces between the resin-impregnated reinforcing member sheets. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent No. 3413356 [Patent Document 2] Japanese Patent No. 5855401 [Patent Document 3] Japanese Patent Application Publication No. 9-117922 [Patent Document 4] Japanese Patent Publication No. 2020-179549 Summary of the Invention [Problem to be solved by the invention]

[0008] However, when multiple materials with different fluidities are molded together in a mold, there is a problem that the material with higher fluidity flows within the mold, causing the material with lower fluidity to shift position within the mold.

[0009] In the method of Patent Document 1, the skin material is fixed by holding it on the outer periphery of the mold. However, the method of Patent Document 1 cannot be applied to molding in which a material with low fluidity is placed completely inside the mold cavity, such as insert molding.

[0010] In the method of Patent Document 2, a dam portion is provided at the outer peripheral edge of the cavity to prevent the outflow of the discontinuous fiber reinforced thermoplastic resin layer, but no method for fixing the sheet material is described.

[0011] In the method of Patent Document 3, a jig is used to hold the skin material outside the mold. However, the method of Patent Document 3 cannot be applied to molding in which a material with low fluidity is placed completely inside the mold cavity, such as insert molding.

[0012] The method of Patent Document 4 uses a reinforcing member resin-impregnated sheet made of a plain-woven cloth made of glass fibers with a wire diameter of approximately 17 μm, impregnated with polypropylene resin. When using a material in which the reinforcing fibers are continuous and oriented in a specific direction, such as a plain-woven cloth, even slight misalignment (even a few millimeters) in the arrangement when the injection material is introduced and press-molded makes it difficult to obtain the desired physical properties. Therefore, measures such as modifying the molding die to prevent the reinforcing member resin-impregnated sheet from shifting are necessary. In particular, when attempting to impregnate resin between multiple reinforcing members, the process becomes too complicated.

[0013] An object of the present invention is to provide a method for manufacturing a molded body that can prevent the composite material from shifting position within a mold when integrally molding a composite material and a molding material that has higher fluidity than the composite material, without fixing the composite material to the outer periphery of the cavity of the mold. [Means for solving the problem]

[0014] In order to solve the above problems, the present invention provides the following means. <1> A method for manufacturing a molded body integrally molded from a composite material containing reinforcing fibers dispersed in an in-plane direction and a molding material having a higher fluidity than the composite material, A method for producing a molded body, comprising the following steps (1) to (3): (1) a step of fixing the composite material to a first molding die using a plurality of fixing members provided in the first molding die, the first molding die having a cavity with an area larger than that of the composite material in a plan view; (2) moving a second mold toward the composite material fixed to the first mold and bringing the second mold into contact with the composite material; (3) A step of pressing the composite material and the molding material together using the first molding die and the second molding die to form an integral molding. <2> further comprising a step of releasing the fixation of the composite material by the fixing member. <1> A method for producing the molded article according to claim 1. <3> Before the step (1), a step of laminating the molding material onto the composite material is included. <1> or <2> A method for producing the molded article according to claim 1. <4> In the step (1), the composite material is fixed to the first mold so that the molding material is in contact with the first mold. <3> A method for producing the molded article according to claim 1. <5> In the step (1), the composite material is fixed to the first mold so that the molding material is disposed on the opposite side to the first mold. <1> or <2> A method for producing the molded article according to claim 1. <6> After the step (1) and before the step (2), a step of laminating the molding material onto the composite material is included. <1> or <2> A method for producing the molded article according to claim 1. <7> the molding material is an injection molding material, and the method includes a step of injecting the molding material between the first mold and the second mold after the step (2) and before the step (3). <1> or <2> A method for producing the molded article according to claim 1. <8> the molding material is an injection molding material, and the method includes a step of injecting the molding material between the first molding die and the second molding die after the step (2) and before the step of releasing the fixing of the composite material by the fixing member. <2> A method for producing the molded article according to claim 1. <9> injecting the molding material between the first mold and the composite material; <7> or <8> A method for producing the molded article according to claim 1. <10> injecting the molding material between the second mold and the composite material; <7> or <8> A method for producing the molded article according to claim 1. <11> The first mold and the second mold are a pair of male and female molds. <1> ~ <10> 1. A method for producing a molded article according to any one of the preceding claims. <12> The first mold is a fixed mold, and the second mold is a movable mold. <11> A method for producing the molded article according to claim 1. <13> The first mold is a lower mold, and the second mold is an upper mold. <11> or <12> A method for producing the molded article according to claim 1. <14> The fixing member is a hole forming member that forms a hole in the molded body. <1> ~ <13> 1. A method for producing a molded article according to any one of the preceding claims. <15> The reinforcing fibers are randomly distributed in two dimensions along the in-plane direction of the composite material. <1> ~ <14> 1. A method for producing a molded article according to any one of the preceding claims. <16> <12> A method for producing the molded article according to the above item the molding material is an injection molding material, and the method includes a step of injecting the injection molding material between the first mold and the second mold after the step (2) and before the step (3); Injection is performed from the first mold. A method for manufacturing a molded body. <17> <16> A method for producing the molded article according to the above item A method for manufacturing a molded body, wherein a design surface is formed by the second molding die, and the injection molding material is filled between the second molding die and the composite material. <18> <17> A method for producing the molded article according to the above item One or more flow holes are provided in the composite material to allow the injection molding material to pass through, The injection molding material injected from the first mold flows through the flow holes and is injected between the first mold and the second mold. A method for manufacturing a molded body. <19> <18> A method for producing the molded article according to the above item the first mold has a first gate, which is a gate for injecting an injection molding material into the mold, in a region where the composite material is placed in a plan view; A method for manufacturing a molded body. <20> <16> A method for producing the molded article according to the above item A design surface is formed by the second molding die, and a resin sheet is placed between the second molding die and the composite material. A method for manufacturing a molded body. <21> <17> or <20> A method for producing the molded article according to the above item The design surface has a grain pattern formed by the second molding die. A method for manufacturing a molded body. <22> the first mold is a fixed mold and the second mold is a movable mold; A method for manufacturing a molded body by opening and closing the second mold by moving it horizontally, There are at least two fixed members at different height positions. <1> ~ <12> 1. A method for producing a molded article according to any one of the preceding claims. <23> the first mold is a fixed mold and the second mold is a movable mold; A method for manufacturing a molded body by opening and closing the second mold by moving it horizontally, There are at least two fixed members with different horizontal positions, <1> ~ <12> 1. A method for producing a molded article according to any one of the preceding claims. <24> The composite material has a pattern cut and cut shape. <1> ~ <23> 1. A method for producing a molded article according to any one of the preceding claims. <25> The method for manufacturing a molded body according to <19>, having a second gate for injecting the injection molding material into a region other than the region where the composite material is disposed in a plan view of the first mold, where the number n1 of the first gates and the number n2 of the second gates satisfy 0 < n1 < n2, A method for manufacturing a molded body. <26> The method for manufacturing a molded body according to <19> or <25>, where the first mold has a second gate for injecting the injection molding material into a region other than the region where the composite material is disposed in a plan view, where the discharge amount V1 of the injection molding material from the first gate and the discharge amount V2 of the injection molding material from the second gate satisfy 0 < V1 < V2, A method for manufacturing a molded body.

Advantages of the Invention

[0015] According to the method for manufacturing a molded body of the present invention, when integrally molding a composite material and a molding material having higher fluidity than the composite material, the position of the composite material in the mold can be prevented from shifting without fixing the composite material at the outer peripheral portion of the cavity of the mold. By using a composite material containing reinforcing fibers dispersed in the in-plane direction, even if the composite material flows slightly during molding, the basic mechanical properties do not change significantly. Also, the shape followability is improved compared to those using continuous fibers such as plain weave cloth.

Brief Description of the Drawings

[0016] [Figure 1] A cross-sectional view of a molded body 1 according to the first embodiment of the present invention. [Figure 2] A schematic diagram showing a method for manufacturing the molded body 1 of the first embodiment. [Figure 3] A schematic diagram showing a method for manufacturing the molded body 1 of the first embodiment. [Figure 4] A schematic diagram showing a method for manufacturing the molded body 1 of the first embodiment. [Figure 5]2A to 2C are schematic diagrams illustrating a method for producing the molded body 1 of the first embodiment. [Figure 6] 2A to 2C are schematic diagrams illustrating a method for producing the molded body 1 of the first embodiment. [Figure 7] FIG. 1 is a cross-sectional view of a molded body 101 according to a second embodiment of the present invention. [Figure 8] 10A to 10C are schematic diagrams showing a method for producing a molded body 101 according to a second embodiment. [Figure 9] 10A to 10C are schematic diagrams showing a method for producing a molded body 101 according to a second embodiment. [Figure 10] 10A to 10C are schematic diagrams showing a method for producing a molded body 101 according to a second embodiment. [Figure 11] 10A to 10C are schematic diagrams showing a method for producing a molded body 101 according to a second embodiment. [Figure 12] 10A to 10C are schematic diagrams showing a method for producing a molded body 101 according to a second embodiment. [Figure 13] 10A to 10C are schematic diagrams showing a method for producing a molded body 101 according to a second embodiment. [Figure 14] 10A and 10B are schematic diagrams showing a method for producing a molded body 201 according to a third embodiment. [Figure 15] 10A and 10B are schematic diagrams showing a method for producing a molded body 201 according to a third embodiment. [Figure 16] 10A and 10B are schematic diagrams showing a method for producing a molded body 201 according to a third embodiment. [Figure 17] 10A and 10B are schematic diagrams showing a method for producing a molded body 201 according to a third embodiment. [Figure 18] 10A and 10B are schematic diagrams showing a method for producing a molded body 201 according to a third embodiment. [Figure 19] 10A and 10B are schematic diagrams showing a method for producing a molded body 201 according to a third embodiment. [Figure 20] 10A and 10B are schematic diagrams showing a method for producing a molded body 301 according to a fourth embodiment. [Figure 21] 10A and 10B are schematic diagrams showing a method for producing a molded body 301 according to a fourth embodiment. [Figure 22] 10A and 10B are schematic diagrams showing a method for producing a molded body 301 according to a fourth embodiment. [Figure 23] 10A and 10B are schematic diagrams showing a method for producing a molded body 301 according to a fourth embodiment. [Figure 24] 10A and 10B are schematic diagrams showing a method for producing a molded body 301 according to a fourth embodiment. [Figure 25] 10A and 10B are schematic diagrams showing a method for producing a molded body 301 according to a fourth embodiment. [Figure 26] FIG. 4 is a horizontal cross-sectional view showing a first molding die 410 and a second molding die 420 that are provided so as to be able to open and close in the horizontal direction. [Figure 27] FIG. 1 is a perspective view showing a box-shaped molded body 100. [Figure 28] FIG. 1 is a schematic diagram of a composite material in a pattern-cut shape. [Figure 29] FIG. 2 is a front view showing the first molding die in which the pattern-cut composite material is fixed by the fixing member. [Figure 30] 5 is a horizontal cross-sectional view showing a first molding die 510 and a second molding die 520 to which a composite material is fixed by a fixing member 512. FIG. [Figure 31] FIG. 6 is a plan view of a first mold 610. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described in detail. [First embodiment] Fig. 1 is a schematic cross-sectional view of a molded body 1 according to a first embodiment of the present invention, and Figs. 2 to 6 are schematic views showing a manufacturing method of the molded body 1. The molded body 1 is formed by integrally molding a reinforcing part 2 made of a composite material 2A and a main body part 3 made of a molding material 3B having higher fluidity than the composite material 2A.

[0018] [Composite materials] The composite material 2A includes reinforcing fibers and a matrix resin. In the composite material 2A, the reinforcing fibers are dispersed in the in-plane direction within the matrix resin.

[0019] [Reinforced fiber] The reinforcing fiber is preferably at least one selected from the group consisting of carbon fiber, aramid fiber, and glass fiber, and more preferably carbon fiber or glass fiber.

[0020] [Carbon fiber] 1. Carbon fiber in general Commonly known carbon fibers include polyacrylonitrile (PAN)-based carbon fibers, petroleum / coal pitch-based carbon fibers, rayon-based carbon fibers, cellulose-based carbon fibers, lignin-based carbon fibers, and phenol-based carbon fibers. Any of these carbon fibers can be suitably used in the present invention. Among these, polyacrylonitrile (PAN)-based carbon fibers are preferred in the present invention because of their excellent tensile strength. Examples of PAN-based carbon fibers that can be used include the carbon fiber "Tenax" (registered trademark) STS40-24KS (average fiber diameter 7 μm) manufactured by Teijin Limited.

[0021] 2. Carbon fiber sizing agent The carbon fiber may have a sizing agent attached to its surface. When using carbon fiber with a sizing agent attached, the type of sizing agent can be appropriately selected depending on the type of carbon fiber and the type of resin used in the composite material or injection molding material, and is not particularly limited.

[0022] [Glass fiber] 1. Glass fiber in general The glass fiber may be any glass fiber generally referred to as glass fiber. The glass composition is not particularly limited to A-glass, C-glass, E-glass, etc., as specified in JIS R3140:2006, and may contain components such as TiO2, SO3, and P2O5. For example, Nitto Boseki's E-glass RS240QR-483 (count: 2400 g / 1000 m) glass fiber may be used as the glass fiber.

[0023] 2. Glass fiber sizing agent The glass fiber may have a sizing agent attached to its surface. When using glass fiber with a sizing agent attached, the type of sizing agent can be appropriately selected depending on the type of glass fiber and the type of resin, and is not particularly limited. Glass fiber that has been pre-treated with a conventionally known coupling agent such as an organosilane compound, an organotitanium compound, an organoborane compound, or an epoxy compound can be preferably used.

[0024] [Dispersion in the in-plane direction] The reinforcing fibers contained in the composite material are preferably dispersed in the in-plane direction. Dispersion of the reinforcing fibers in the in-plane direction means that the reinforcing fibers are dispersed so that their fiber axes are oriented in the in-plane direction. It is preferable that the angle between the fiber axes of the reinforcing fibers and the in-plane direction is 45° or less.

[0025] 1. In-plane direction The composite material 2A is preferably a plate-shaped material. The in-plane direction is any direction parallel to a plane perpendicular to the thickness direction of the composite material 2A.

[0026] 2. Random distribution in two dimensions The reinforcing fibers are preferably dispersed two-dimensionally and randomly in the in-plane direction of the composite material 2 A. When the composite material 2 A is press-molded without flowing, the shape of the reinforcing fibers is largely maintained before and after molding, and therefore, it is preferable that the reinforcing fibers contained in the reinforced part 2 molded from the composite material 2 A are also dispersed two-dimensionally and randomly in the in-plane direction. Here, "dispersed two-dimensionally at random" refers to a state in which the reinforcing fibers are oriented randomly within the plane of the composite material 2A or the reinforcing portion 2, rather than in a specific direction such as one direction, and are arranged within the sheet plane overall without showing any specific directionality. The composite material 2A (or the reinforcing portion 2) obtained using discontinuous fibers dispersed in this two-dimensionally at random does not have anisotropy within the plane and is substantially isotropic.

[0027] The degree of orientation, which indicates the degree to which the reinforcing fibers are randomly dispersed in two dimensions in the in-plane direction of the composite material 2A or the reinforcing portion 2, is evaluated by calculating the ratio of the tensile modulus of the composite material 2A in two mutually intersecting directions. The reinforcing fibers can be evaluated as being randomly dispersed in two dimensions if the ratio (Eδ) obtained by dividing the larger of the tensile modulus values ​​measured in any direction of the composite material 2A (or the reinforcing portion 2) by the smaller of the two measured values ​​is 5 or less, more preferably 2 or less, and even more preferably 1.5 or less. When the reinforcing portion 2 has a curved surface, the degree of random dispersion of the reinforcing fibers in the in-plane direction of the reinforcing portion 2 (degree of orientation) can be evaluated by heating the molded product 1 to above its softening temperature to return it to a flat plate shape, removing only the reinforcing portion 2, and solidifying it. Then, a test piece is cut from the reinforcing portion 2 that has been returned to its flat shape, and the tensile modulus of the test piece in two mutually intersecting directions can be measured to evaluate the two-dimensional random dispersion in the reinforcing portion 2.

[0028] [Fiber length of reinforcing fibers contained in composite material] The weight average fiber length LwA of the reinforcing fibers contained in the composite material 2A is preferably 1 mm or more, and more preferably 3 mm or more. If LwA is 100 mm or less, the fluidity of the material is less likely to decrease when the composite material 2A is press-molded to produce the reinforcing portion 2 in a desired shape. Furthermore, if LwA is 1 mm or more, the mechanical strength of the resulting reinforcing portion 2 is less likely to decrease, which is preferable.

[0029] Since the weight-average fiber length LwA of the reinforcing fibers contained in composite material 2A does not change before and after molding, by examining the weight-average fiber length of the reinforcing fibers contained in reinforced part 2, the weight-average fiber length LwA of the reinforcing fibers contained in composite material 2A can be determined. The weight average fiber length LwA of the reinforcing fibers contained in the composite material 2A is preferably 3 mm or more and 100 mm or less, more preferably 3 mm or more and 80 mm or less, and even more preferably 5 mm or more and 60 mm or less. The weight average fiber length of the reinforcing fibers can be calculated by the formula (1) described below.

[0030] [Forming material] The forming material 3B that forms the main body portion 3 includes a matrix resin. Further, the forming material 3B preferably includes reinforcing fibers. The reinforcing fibers contained in the forming material 3B are preferably the carbon fibers or glass fibers described above. The forming material 3B has a higher fluidity than the composite material 2A. The forming material 3B having a higher fluidity than the composite material 2A can be created by making the fiber volume ratio (Vf) of the forming material 3B lower than the fiber volume ratio (Vf) of the composite material 2A. Also, by making the weight average fiber length of the reinforcing fibers contained in the forming material 3B shorter than the weight average fiber length of the reinforcing fibers contained in the composite material 2A, the fluidity of the forming material 3B can be made higher than the fluidity of the composite material 2A.

[0031] [Fiber length of reinforcing fibers contained in the forming material] The forming material 3B includes reinforcing fibers with a weight average fiber length LwB, and it is preferable that LwB < LwA. When LwB < LwA, the mechanical strength of the reinforcing portion 2 formed by the composite material 2A becomes higher than the mechanical strength of the main body portion 3 formed by the forming material 3B, so the formed body 1 can be reinforced by the reinforcing portion 2.

[0032] Note that the forming material 3B may be an injection molding material. When the forming material 3B is injected into a mold to form the main body portion 3, the forming material 3B immediately before injection is called an injection molding material. If there is a kneading process for the forming material 3B before injection, the kneaded forming material 3B is called an injection molding material.

[0033] The weight average fiber length LwB of the reinforcing fibers contained in the forming material 3B is preferably less than 3 mm. The weight average fiber length LwB is more preferably 0.01 mm or more and less than 3 mm. The lower limit of the weight average fiber length LwB is preferably 0.01 mm or more, more preferably 0.05 mm or more, and still more preferably 0.1 mm or more. When the weight average fiber length LwB is 0.01 mm or more, the mechanical strength of the main body portion 3 is ensured. On the other hand, the upper limit of the weight average fiber length LwB is preferably less than 3 mm, more preferably less than 2 mm, and still more preferably less than 1 mm.

[0034] When the weight-average fiber length LwB is 1.0 mm or less, the main body 3 can be manufactured from an injection molding material kneaded with molding material 3B. Generally, the weight-average fiber length LwB of the reinforcing fibers contained in an injection molding material sufficiently kneaded with molding material 3B is less than 1 mm. The weight average fiber length of the reinforcing fibers can be calculated by the formula (1) described below.

[0035] [Weight average fiber length Lw] Generally, the fiber length of each reinforcing fiber is L i Then, the weight average fiber length Lw can be calculated by the following formula (1): The unit of the weight average fiber length Lw is mm.

number

[0036] Here, "I" indicates the number of reinforcing fibers measured. The reinforcing fibers can be extracted from the reinforcing portion 2 and the main body portion 3 by, for example, performing a heat treatment at 500° C. for about 1 hour and removing the matrix resin in a furnace. The weight average fiber length Lw is, for example, the fiber lengths L1 to L2 of 100 fibers (I=100) randomly extracted from the reinforcement portion 2 and the main body portion 3 after the heat treatment. 100 can be measured to the nearest 1 mm using a caliper or the like and calculated based on formula (1).

[0037] If the material contains short reinforcing fibers that cannot be measured with a caliper, after removing the matrix resin, the resulting reinforcing fibers are placed in water containing a surfactant, and thoroughly stirred with ultrasonic vibrations. The stirred dispersion of reinforcing fibers is randomly sampled with a measuring spoon to obtain an evaluation sample, and the length of 3,000 reinforcing fibers (I = 3,000) is measured using the Luzex AP image analyzer manufactured by Nireco Corporation. The measured fiber lengths L1 to L 3000 Using this, the weight average fiber length Lw can be calculated in the same manner as in the above formula (1).

[0038] [Volume ratio of reinforcing fibers in composite materials and molding materials] The volume fraction (Vf) of the reinforcing fibers of each of the composite material 2A and the molding material 3B can be calculated by the following formula (2). There are no particular limitations on the volume fraction of the reinforcing fibers, but the volume fraction (Vf) of the reinforcing fibers is preferably 10 to 60 Vol%, more preferably 20 to 50 Vol%, and even more preferably 25 to 45 Vol%. Volume fraction of reinforcing fiber (Vf) = 100 × volume of reinforcing fiber / (volume of reinforcing fiber + volume of resin) Equation (2) In the present invention, it is preferable for the manufacturing process that the volume fraction Vfb of the reinforcing fibers in molding material 3B and the volume fraction Vfa of the carbon fibers in composite material 2A satisfy the relationship Vfa ≥ Vfb. For example, when molding material 3B is made from crushed scraps of composite material 2A recovered from the manufacturing process or product, or when the main body 3 is manufactured using molding material 3B made from crushed scraps and then added with a thermoplastic resin, Vfa > Vfb is often satisfied. In other words, employing a manufacturing method that satisfies Vfa ≥ Vfb allows for efficient use of scraps remaining after cutting out composite material 2A and facilitates material recycling. Vfa is preferably 20 to 45 Vol %, more preferably 25 to 40 Vol %. Vfb is preferably 1 to 40 Vol %, more preferably 5 to 30 Vol %, and even more preferably 10 to 25 Vol %.

[0039] [Analysis of reinforcing fiber volume fraction (Vf)] Although there is no limitation on the analysis of the reinforcing fiber volume fraction, it is recommended to measure it as follows. A sample is cut from the reinforcing part 2 or the main part 3, and the resin is burned off in a furnace at 500°C for 1 hour. The mass of the sample before and after treatment is weighed to calculate the mass of the reinforcing fiber and resin. Next, the volume ratio of the reinforcing fiber to the resin is calculated using the specific gravity of each component. Vf = 100 × reinforcing fiber volume / (reinforcing fiber volume + resin volume)

[0040] [resin] The matrix resin contained in the composite material 2A and the matrix resin contained in the molding material 3B may be either thermosetting or thermoplastic.

[0041] 1.Thermoplastic resin 1.1 Overview When the resin used is a thermoplastic resin, the type is not particularly limited, and a resin having a desired softening point or melting point can be appropriately selected and used. As the thermoplastic resin, one having a softening point in the range of 180°C to 350°C is usually used, but is not limited thereto.

[0042] Examples of thermoplastic resins include polyolefin resins, polystyrene resins, polyamide resins, polyester resins, polyacetal resins (polyoxymethylene resins), polycarbonate resins, (meth)acrylic resins, polyarylate resins, polyphenylene ether resins, polyimide resins, polyethernitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyether ketone resins, thermoplastic urethane resins, fluorine-based resins, and thermoplastic polybenzimidazole resins.

[0043] The thermoplastic resin used in the composite material 2A and the molding material 3B may be one type or two or more types. Examples of the use of two or more types of thermoplastic resins in combination include, but are not limited to, the use of thermoplastic resins having different softening points or melting points, or the use of thermoplastic resins having different average molecular weights. When a thermoplastic resin is used, it is more preferable to use a polyolefin resin, and even more preferable to use a polypropylene resin.

[0044] 1.2 Resins for composite materials and molding materials The resin contained in composite material 2A is preferably a thermoplastic resin. When the resin contained in composite material 2A is a thermoplastic resin, it is more preferable that the resins contained in composite material 2A and molding material 3B are the same type of thermoplastic resin.

[0045] 2.Thermosetting resin The resin contained in the composite material 2A may be a thermosetting resin. In this case, the composite material 2A may be a sheet molding compound using reinforcing fibers. Due to its high moldability, the sheet molding compound can be easily molded into even complex shapes. The sheet molding compound has higher fluidity and formability than continuous fibers, making it easy to create ribs and bosses.

[0046] [Other agents] The resin used in the composite material 2A and the molding material 3B may contain additives such as various fibrous or non-fibrous fillers such as organic or inorganic fibers, flame retardants, UV-resistant agents, stabilizers, release agents, pigments, softeners, plasticizers, surfactants, etc., within the scope of the present invention.

[0047] [Preferable resin and fiber combinations] [fiber] It is preferable that the reinforcing fibers contained in the composite material 2A are glass fibers and / or carbon fibers, and that the reinforcing fibers contained in the molding material 3B are glass fibers. The reinforcing fibers contained in the composite material 2A may be partially carbon fiber, and glass fiber may be used in the remaining portions. The carbon fiber is preferably used in the composite material 2A in the vicinity of the holes 2H (described later) in the reinforcing portion 2.

[0048] [resin] The resin contained in composite material 2A may be a thermoplastic resin or a thermosetting resin, and the resin contained in molding material 3B may be a thermoplastic resin or a thermosetting resin. While molding material 3B contains a thermoplastic resin, a thermosetting sheet molding compound may be used for composite material 2A.

[0049] It is preferable that the volume Va of the composite material 2A used in the reinforcing portion 2 and the volume Vb of the molding material 3B used in the main body portion 3 satisfy the relationship Vb≧Va. Va:Vb is preferably 10:90 to 50:50, and more preferably 20:80 to 40:60.

[0050] [Manufacturing method] Next, we will explain how to manufacture the molded body 1. In this embodiment, the molded body 1 is integrally molded from a composite material 2A containing reinforcing fibers dispersed in the in-plane direction and a molding material 3B having higher fluidity than the composite material 2A.

[0051] The method for producing the molded body 1 includes the following steps (1) to (3): (1) A step of fixing a composite material 2A to a first molding die 10 using a plurality of fixing members 12 provided on the first molding die 10, which has a cavity 11 with an area larger than that of the composite material 2A in a planar view; (2) A step of moving a second molding die 20 toward the composite material 2A fixed to the first molding die 10 and bringing the second molding die 20 into contact with the composite material 2A; (3) A step of pressing the composite material 2A and the molding material 3B together using the first molding die 10 and the second molding die 20 to form them into a single unit.

[0052] Molding material 3B may be introduced into the mold at any timing prior to step (3). For example, a step of laminating molding material 3B onto composite material 2A may be included prior to step (1). That is, in step (1), it is preferable that, with composite material 2A and molding material 3B in a laminated state, the laminate of composite material 2A and molding material 3B is fixed in cavity 11 of first mold 10 by a plurality of fixing members 12. In this case, in step (1), it is preferable to fix composite material 2A to first molding die 10 so that molding material 3B comes into contact with first molding die 10.

[0053] When the resin contained in the composite material 2A and the molding material 3B is a thermoplastic resin, it is preferable to use cold press molding.

[0054] The manufacturing method for producing a molded body 1 by cold press molding includes the following steps (0) to (3): (0) a step of heating a composite material 2A and a molding material 3B to a first predetermined temperature; (1) a step of fixing the composite material 2A and the molding material 3B to a first molding die 10 using a plurality of fixing members 12 provided on the first molding die 10, which has a cavity 11 with an area larger than that of the composite material 2A in a planar view; (2) a step of moving a second molding die 20 toward the composite material 2A fixed to the first molding die 10 and bringing the second molding die 20 into contact with the composite material 2A; (3) a step of pressing the composite material 2A and the molding material 3B together using the first molding die 10 and the second molding die 20 to mold them into a single unit.

[0055] (0) Step of heating the composite material 2A to a first predetermined temperature It is preferable that composite material 2A be preheated to a first predetermined temperature. If the thermoplastic resin contained in composite material 2A is crystalline, the first predetermined temperature is a temperature above the melting point and below the decomposition temperature of the thermoplastic resin. If the thermoplastic resin contained in composite material 2A is amorphous, the first predetermined temperature is a temperature above the glass transition temperature and below the decomposition temperature of the thermoplastic resin.

[0056] In the case of cold press molding, the temperatures of the first molding die 10 and the second molding die 20 are adjusted to a second predetermined temperature. If the thermoplastic resin contained in the composite material 2A is crystalline, the second predetermined temperature is a temperature below the melting point of the thermoplastic resin. If the thermoplastic resin contained in the composite material 2A is amorphous, the second predetermined temperature is a temperature below the glass transition temperature of the thermoplastic resin. In this way, by adjusting the temperatures of the composite material 2A and the first molding die 10, the cold pressing can be carried out suitably.

[0057] First, as shown in FIG. 2, a composite material 2A is fixed in a cavity 11 of a first molding die 10 by a plurality of fixing members 12. The fixing member 12 may be, for example, a slide core that forms a hole 1H in the molded body 1. For example, the composite material 2A may be provided with a hole 2H in advance, and the fixing member 12 may be inserted into the hole 2H to fix the composite material 2A. Alternatively, the composite material 2A may be fixed by piercing a pin-shaped fixing member 12 into the composite material 2A. In this case, the hole 2H may not be provided in the composite material 2A.

[0058] The composite material 2A may be pre-shaped and placed in the cavity 11 of the first molding die 10 so as to fit the cavity 11 of the first molding die 10.

[0059] Next, as shown in FIG. 3, the second molding die 20 is moved toward the composite material 2A fixed to the first molding die 10, and the second molding die 20 is brought into contact with the composite material 2A.

[0060] 4, the composite material 2A and the molding material 3B are pressed together using a first molding die 10 and a second molding die 20 to form an integral mold. The molding pressure is not particularly limited, but is preferably less than 20 MPa, and more preferably 10 MPa or less. In this way, when composite material 2A and molding material 3B are pressed together, molding material 3B, which has higher fluidity than composite material 2A, flows within the mold. Even in this case, composite material 2A is fixed by fixing member 12, so that it is possible to prevent the position of composite material 2A from shifting.

[0061] When composite material 2A and molding material 3B are pressed together, holes 2H are formed in composite material 2A at positions corresponding to fixing member 12, and holes 3H are formed in molding material 3B at positions corresponding to fixing member 12. In other words, fixing member 12 is a hole-forming member that forms holes 1H in molded body 1. A hole 22 into which the fixing member 12 is inserted may be provided at a position of the second molding die 20 facing the fixing member 12.

[0062] Thereafter, second molding die 20 is moved in a direction away from first molding die 10, and molded body 1 is removed from first molding die 10. In this way, molded body 1 is completed.

[0063] 5, fixing member 12 may be moved and pulled out from integrally molded composite material 2A and molding material 3B. This releases fixing of composite material 2A by fixing member 12. That is, the method may further include a step of releasing fixing of composite material 2A by fixing member 12. Note that fixing of composite material 2A by fixing member 12 may be released after step (2), before step (3), or after step (3).

[0064] If no hole 1H is formed in the molded body 1, the fixing member 12 can be moved as shown in Fig. 6 before the composite material 2A and the molding material 3B are pressed together to form an integral body. That is, the fixing of the composite material 2A by the fixing member 12 can be released after step (2) and before step (3). In this case, even if the hole 2H is formed in the composite material 2A at a position corresponding to the fixing member 12, when the composite material 2A and the molding material 3B are pressed together using the first molding die 10 and the second molding die 20 to form an integral body, the molding material 3B flows into the hole 2H, thereby filling the hole 2H.

[0065] By integrally molding the reinforcing portion 2 and the main body portion 3 in this manner, a molded body 1 having excellent bonding strength between the reinforcing portion 2 and the main body portion 3 can be obtained. Furthermore, by placing a plate-shaped composite material 2A in a molding die and pressing the composite material 2A and a molding material 3B that is more fluid than the composite material 2A, a molded body 1 with a complex shape having ribs and bosses can be produced.

[0066] [Second embodiment] Next, a method for manufacturing a molded article according to the second embodiment will be described. Note that the same components as those in the first embodiment will be assigned the same reference numerals as the last two digits, and the description thereof will be omitted. In the second embodiment, similarly to the first embodiment, the composite material 102A and the molding material 103B may be integrally molded by cold pressing.

[0067] FIG. 7 is a schematic cross-sectional view of a molded body 101 according to the second embodiment of the present invention, and FIGS. 8 to 13 are schematic views showing a method for manufacturing the molded body 101. As shown in FIG. In the first embodiment, molding material 3B was arranged so as to be in contact with first molding die 10, but in the second embodiment, molding material 103B is arranged so as to be in contact with second molding die 20. In other words, composite material 102A is fixed to first molding die 10 so that molding material 103B is arranged on the opposite side from first molding die 10.

[0068] The manufacturing method for producing the molded body 101 of the second embodiment includes the following steps (1) to (3): (1) a step of fixing the composite material 102A to the first molding die 10 using a plurality of fixing members 12 provided on the first molding die 10 having a cavity 11 with an area larger than that of the composite material 102A in a planar view; (2) a step of moving the second molding die 20 toward the composite material 102A fixed to the first molding die 10 and bringing the second molding die 20 into contact with the composite material 102A; (3) a step of pressing the composite material 102A and the molding material 103B together using the first molding die 10 and the second molding die 20 to mold them into a single unit.

[0069] Specifically, first, as shown in FIG. 8, composite material 102A is fixed in cavity 11 of first molding die 10 by a plurality of fixing members 12. Next, as shown in FIG. 9, before step (2), molding material 103B is laminated on composite material 102A fixed to first molding die 10. Note that a step of laminating molding material 103B on composite material 102A may be included before step (1). In this case, in step (1), it is preferable to fix the laminate of composite material 102A and molding material 103B to first molding die 10 so that molding material 103B is located on the opposite side of first molding die 10. That is, in step (1), as shown in FIG. 9, the laminate of composite material 102A and molding material 103B may be fixed by a plurality of fixing members 12 within cavity 11 of first molding die 10 so that molding material 103B is located on the opposite side of first molding die 10.

[0070] 10, second molding die 20 is moved toward composite material 102A fixed to first molding die 10, and second molding die 20 is brought into contact with composite material 102A. At this time, second molding die 20 may come into contact with molding material 103B layered on composite material 102A.

[0071] 11, composite material 102A and molding material 103B are pressed together using first molding die 10 and second molding die 20. At this time, holes 102H are formed in composite material 102A at positions corresponding to fixing member 12, and holes 103H are formed in molding material 103B at positions corresponding to fixing member 12.

[0072] Thereafter, second molding die 20 is moved in a direction away from first molding die 10, and molded body 101 is removed from first molding die 10. In this way, molded body 101 is completed.

[0073] 12, fixing member 12 may be moved and pulled out from integrally molded composite material 102A and molding material 103B. This releases fixing of composite material 102A by fixing member 12. That is, the method may further include a step of releasing fixing of composite material 102A by fixing member 12. Note that fixing of composite material 102A by fixing member 12 may be released after step (2), before step (3), or after step (3).

[0074] If hole 101H is not to be formed in molded body 101, fixing member 12 can be moved as shown in Fig. 13 before composite material 102A and molding material 103B are pressed together to form an integral body. That is, fixing of composite material 102A by fixing member 12 can be released after step (2) and before step (3). In this case, even if hole 102H is formed in composite material 102A at a position corresponding to fixing member 12, when composite material 102A and molding material 103B are pressed together using first molding die 10 and second molding die 20 to form an integral body, molding material 103B flows into hole 102H, thereby filling hole 102H.

[0075] [Third embodiment] 14 to 19 are schematic diagrams showing a method for producing a molded body 201 according to the third embodiment of the present invention. Note that the same components as those in the first embodiment are given the same reference numerals with the same last two digits, and the description thereof will be omitted. In the third embodiment, injection molding material 203B is used as a molding material having higher fluidity than the composite material. The third embodiment includes a step of injecting molding material (injection molding material 203B) between first molding die 210 and second molding die 220 after step (2) and before step (3) of the first embodiment.

[0076] Specifically, the manufacturing method for producing the molded body 201 of the third embodiment includes the following steps (1) to (3): (1) a step of fixing the composite material 202A to the first molding die 210 using a plurality of fixing members 212 provided on the first molding die 210 having a cavity 211 with an area larger than that of the composite material 202A in a planar view; (2) a step of moving the second molding die 220 toward the composite material 202A fixed to the first molding die 210 and bringing the second molding die 220 into contact with the composite material 202A; (3) a step of injecting the injection molding material 203B between the first molding die 210 and the second molding die 220; and (4) a step of pressing the composite material 202A and the injection molding material 203B together using the first molding die 210 and the second molding die 220 to mold them into a single piece.

[0077] The following step may be included before step (1): (0) Heating the composite material 202A to a first predetermined temperature. In this case, the first molding die 210 and the second molding die 220 are set to a second predetermined temperature.

[0078] Specifically, first, as shown in FIG. 14, composite material 202A is fixed in cavity 211 of first molding die 210 by a plurality of fixing members 212.

[0079] Next, as shown in FIG. 15, the second molding die 220 is moved toward the composite material 202A fixed to the first molding die 210, and the second molding die 220 is brought into contact with the composite material 202A.

[0080] Next, as shown in FIG. 16 , injection molding material 203B is injected between first molding die 210 and composite material 202A through gate 213 provided in first molding die 210. Note that injection molding material 203B may be injected immediately before or immediately after pressure begins to be applied to a portion of composite material 202A from second molding die 220. To prevent composite material 202A from shifting position within the molding die, it is preferable to inject injection molding material 203B immediately after second molding die 220 comes into contact with at least a portion of composite material 202A and pressure begins to be applied to composite material 202A. Note that the method for injecting injection molding material 203B into the molding die is not particularly limited, and can be performed using a conventionally known method. At this time, composite material 202A is pressed against second mold 220 by the pressure of injection molding material 203B.

[0081] Injection molding material 203B is preferably kneaded and filled between first molding die 210 and composite material 202A. By pressing injection molding material 203B after filling the mold, it is possible to prevent composite material 202A from shifting in position.

[0082] When the injection molding material 203B is poured into the mold, it is preferably heated to a temperature above the melting point and below the decomposition temperature of the thermoplastic resin if the thermoplastic resin contained in the injection molding material 203B is crystalline, or above the glass transition temperature and below the decomposition temperature of the thermoplastic resin if the thermoplastic resin is amorphous.

[0083] To fill the space between first molding die 210 and composite material 202A with injection molding material 203B, it is sufficient to stop the descent of second molding die 220 once before the molding die is completely closed. The descent of second molding die 220 is preferably stopped after second molding die 220 comes into contact with composite material 202A. By restricting the movement of composite material 202A by having composite material 202A come into contact with second molding die 220, it is possible to prevent composite material 202A from shifting position during pressing.

[0084] Next, as shown in FIG. 17, composite material 202A and injection molding material 203B are pressed in a mold to be integrally molded. At this time, hole 202H is formed in composite material 202A at a position corresponding to fixing member 212, and hole 203H is formed in injection molding material 203B at a position corresponding to fixing member 212. In other words, fixing member 212 is a hole forming member that forms hole 201H in molded body 201. A hole 222 into which the fixing member 212 is inserted may be provided at a position of the second molding die 220 facing the fixing member 212. Thereafter, second molding die 220 is moved in a direction away from first molding die 210, and molded body 201 is removed from first molding die 210. In this way, molded body 201 is completed.

[0085] In this way, injection molding material 203B is injected into the mold while composite material 202A is fixed by fixing member 212, so even if injection molding material 203B flows within the mold, the position of composite material 202A can be prevented from shifting.

[0086] 18, fixing member 212 may be moved and pulled out from integrally molded composite material 202A and injection molding material 203B. This releases composite material 202A from fixing member 212. That is, the method may further include a step of releasing composite material 202A from fixing member 212. The fixing of composite material 202A by fixing member 212 may be released after step (3) or before step (4), or after step (4). After step (2) of bringing second molding die 220 into contact with composite material 202A and before the step of releasing the fixation of composite material 202A, a step of injecting injection molding material 203B between first molding die 210 and composite material 202A may be included.

[0087] 19, before composite material 202A and injection molding material 203B are pressed together to form an integral body. That is, after step (3) and before step (4), composite material 202A is released from fixation by fixation member 212. In this case, even if hole 202H is formed in composite material 202A at a position corresponding to fixation member 212, injection molding material 203B flows into hole 202H when composite material 202A and injection molding material 203B are pressed together using first molding die 210 and second molding die 220 to form an integral body, thereby filling hole 202H.

[0088] [Fourth embodiment] 20 to 25 are schematic diagrams showing a method for producing a molded body 301 according to the fourth embodiment of the present invention. Note that the same components as those in the third embodiment are given the same reference numerals with the same last two digits, and the description thereof will be omitted. The fourth embodiment differs from the third embodiment in that injection molding material 303B is injected between second mold 320 and composite material 302A.

[0089] Specifically, first, as shown in FIG. 20, composite material 302A is fixed in cavity 311 of first molding die 310 by a plurality of fixing members 312.

[0090] Next, as shown in FIG. 21, second molding die 320 is moved toward composite material 302A fixed to first molding die 310, and second molding die 320 is brought into contact with composite material 302A.

[0091] Next, as shown in FIG. 22, injection molding material 303B is injected through gate 323 provided in second molding die 320 into the space between second molding die 320 and composite material 302A.

[0092] Next, as shown in FIG. 23, composite material 302A and injection molding material 303B are pressed in a mold to be integrally molded. At this time, holes 302H are formed in the composite material 302A at positions corresponding to the fixing members 312, and holes 303H are formed in the injection molding material 303B at positions corresponding to the fixing members 312. A hole 322 into which the fixing member 312 is inserted may be provided at a position of the second molding die 320 facing the fixing member 312 . Thereafter, second molding die 320 is moved in a direction away from first molding die 310, and molded body 301 is removed from first molding die 310. In this way, molded body 301 is completed.

[0093] 24, fixing member 312 may be moved and pulled out from integrally molded composite material 302A and injection molding material 303B. This releases composite material 302A from fixing member 312. That is, the method may further include a step of releasing composite material 302A from fixing member 312. Composite material 302A may be released from fixing member 312 after step (3) or before step (4), or after step (4). After step (2) of bringing second molding die 320 into contact with composite material 302A and before the step of releasing composite material 302A from fixation, a step of injecting injection molding material 303B between second molding die 320 and composite material 302A may be included.

[0094] 25, before composite material 302A and injection molding material 303B are pressed together to form an integral mold. That is, after step (3) and before step (4), composite material 302A is released from fixation by fixation member 312. In this case, even if hole 302H is formed in composite material 302A at a position corresponding to fixation member 312, injection molding material 303B will flow into hole 302H and fill hole 302H when composite material 302A and injection molding material 303B are pressed together using first molding die 310 and second molding die 320 to form an integral mold.

[0095] In the above first to fourth embodiments, a pair of male and female molds, a first mold and a second mold, are used, and the first mold is a fixed mold and the second mold is a movable mold. However, the present invention is not limited to this. For example, the first mold may be a movable mold and the second mold may be a fixed mold.

[0096] In the above explanation, the first mold is the lower mold, the second mold is the upper mold, and the second mold opens and closes by moving up and down toward the first mold, but for example, the first mold may open and close by moving up and down toward the second mold. Alternatively, the first mold and the second mold may open and close by moving at least one of them horizontally.

[0097] [Mold opening and closing direction] When the first molding die is a fixed die and the second molding die is a movable die, and a molded body is produced by moving the second molding die horizontally toward the first molding die to open and close the second molding die, it is preferable to have at least two fixing members at different height positions. FIG. 26 is a horizontal cross-sectional view showing a first molding die 410 and a second molding die 420 that are arranged to be able to open and close horizontally. In FIG. 26, the first molding die 410 is a fixed die, and the second molding die 420 is a movable die. The first molding die 410 has a fixing member 412 and a gate 413. The first molding die 410 is provided with a plurality of fixing members 412 that fix the composite material 402A to the first molding die 410. It is preferable that the multiple fixing members 412 are located at different horizontal positions. By providing the multiple fixing members 412 at different horizontal positions on the first molding die 410, it is possible to prevent the composite material 412A from shifting in position relative to the first molding die 410. The fixing members 412 may be provided at different positions in the height direction. Three or more fixing members 412 may be provided at different positions in the height direction and horizontal direction. In addition, second molding die 420 may be provided with hole 422 at a position facing fixing member 412, into which fixing member 412 is inserted.

[0098] [Fixed and movable types] Depending on the mold, the fixed mold may move. If the fixed mold moves, the mold that moves a relatively small distance is called the fixed mold, and the mold that moves a relatively large distance is called the movable mold.

[0099] [Pattern Cut] The composite material is preferably cut into a shape obtained by pattern cutting. Pattern cutting refers to a composite material that is pre-cut into a desired shape to match the shape of the molded product. It does not refer to a simple shape such as a square or rectangle. For example, when manufacturing a box-shaped molded product 501 as shown in FIG. 27, a composite material 502A may be formed into a shape with margins added to the portions that make up the developed view of the box, as shown in FIG. 28. In FIG. 28, four portions 502A2 that will become the side surfaces are provided around a portion 502A1 that will become the bottom surface of the rectangular box, and a margin 502A3 is provided at the portion where the adjacent portions 502A2 that will become the side surfaces are joined during molding. Note that, although a margin 502A3 is provided only on one of the two adjacent portions 502A2 that will become the side surfaces in FIG. 28, a margin 502A3 may be provided on both sides.

[0100] When the resin contained in the composite material is a thermoplastic resin and the molding method is cold pressing, it is particularly preferable for the composite material to have a shape that has been pattern-cut. In the case of cold pressing, the resin begins to solidify the moment the molding die comes into contact with the composite material, so the fluidity during molding is lower than that of thermosetting resins. Therefore, if the composite material is cut into the desired shape in advance, it is easier to create a molded product of the desired shape. The pattern-cut shape is preferably a shape developed by computer inverse molding analysis from the three-dimensional shape of the press-molded product to be manufactured.

[0101] [Pattern cutting and fixing parts] The fixing member exerts a more effective effect when the composite material is pattern-cut into a cut shape, the first molding die is fixed, the second molding die is movable, and the molded body is produced by opening and closing the second molding die by moving it horizontally. Fig. 29 is a front view showing first molding die 510 in which pattern-cut composite material 502A is fixed by fixing members 512. As shown in Fig. 29, it is preferable to fix the composite material to first molding die 510 by fixing members 512 at multiple locations spaced apart in the horizontal direction in portion 502A1 that will become the bottom surface of a rectangular box, for example.

[0102] FIG. 30 is a horizontal cross-sectional view showing first molding die 510 and second molding die 520 to which a composite material is fixed by fixing members. When the molding die opens and closes horizontally (left and right in FIG. 30), the composite material needs to be positioned so that the plate surface faces up and down (perpendicular to the paper surface of FIG. 30). In this case, when a pattern-cut composite material 502A is used, there is a possibility that the composite material 502A will sag in an unintended direction compared to a composite material with a simple shape such as a square or rectangle. Therefore, by appropriately fixing the composite material 502A to the first molding die 510 using fixing members 512, it is possible to effectively prevent the composite material 502A from sagging in an unintended direction. In Figure 29, the composite material may be pre-shaped so that side portion 502A2 and margin 502A3, which are above bottom portion 502A1 fixed to first molding die 510 by fixing member 512, do not collapse toward second molding die 520 (see Figure 30), but collapse toward first molding die 510.

[0103] [Injection from a fixed mold and design] Injection from a fixed mold and design will be explained below. In the method for producing a molded article of the present invention, the first mold is a fixed mold, the second mold is a movable mold, the molding material is an injection molding material, and the method includes a step of injecting the injection molding material between the first mold and the second mold after step (2) and before step (3), and the injection is preferably carried out from the first mold, which is a fixed mold. Compared to injecting from a movable mold, injecting from a fixed mold is preferable because the equipment does not become too complicated.

[0104] 1. Formation of design surface When injection is performed from the first mold, which is a fixed mold, it is preferable that the design surface be formed by the second mold, which is a movable mold. This is because a trace of the injection gate remains on the surface formed by the first mold, which is a fixed mold, while no trace of the injection gate remains on the surface formed by the second mold, which is a movable mold. At this time, the design property of the molded body can be improved by devising, for example, the following between the composite material and the second mold. In the present invention, the layer formed between the composite material and the second mold may be referred to as a skin layer.

[0105] 2. Composite Material and Design Surface When injection is performed from the first mold, which is a fixed mold, it is preferable to fill the injection molding material between the second mold and the composite material. By filling the injection molding material between the second mold, which is a movable mold, and the composite material, the fibers contained in the composite material can be hidden. By filling the injection molding material between the second mold and the composite material, a skin layer is formed. As will be described later, the skin layer can be formed, for example, by a method of causing the injection molding material to flow around from the outside of the composite material, a method of flowing the injection molding material through the flow holes formed in the composite material, a method of previously arranging a resin sheet between the composite material and the second mold, and the like. The thickness of the skin layer is preferably 50 μm or more and 300 μm or less, and preferably 70 μm or more and 200 μm or less.

[0106] 2.1 Gate Position and Number In order to form a skin layer with the injection molding material, the injection molding material may be filled so as to enter between the composite material and the cavity wall surface of the mold. In this case, it is preferable that the number of gates for injecting the injection molding material satisfies 0 < n1 < n2. Here: n1 is the number of the first gates provided in the region (XA) where the composite material is arranged in the plan view of the cavity of the mold; n2 is the number of the second gates provided in the region other than the region (XA) where the composite material is arranged in the plan view of the cavity of the mold.

[0107] For example, in the example shown in FIG. 31, in the first mold 610, two gates 613a are provided in the region Y1, two gates 613b are provided in the region XA, and two gates 613c are provided in the region Y2. The region XA is the region where the composite material is disposed, and the regions Y1 and Y2 are regions other than the region (XA) where the composite material is disposed. The gate 613b is the first gate provided in the region XA, and the gates 613a and 613c are the second gates provided in regions other than the region XA. In this case, n1 = 2, n2 = 4, and 0 < n1 < n2 is satisfied. When 0 < n1 < n2 is satisfied, the injection molding material ejected from the gates 613a and 613c spreads to the region where the composite material is disposed, so that it can be promoted that the injection molding material enters between the composite material and the cavity wall surface of the second mold (preferably the movable mold).

[0108] 2.2 Gate position and discharge volume In order to form a skin layer with the injection molding material, the injection molding material may be filled so as to enter between the composite material and the cavity wall surface of the mold. In this case, it is preferable that the discharge volume from the gate for injecting the injection molding material satisfies 0 < V1 < V2. Here: V1 is the discharge volume of the injection molding material from the first gate provided in the region (XA) where the composite material is disposed in the plan view of the cavity of the mold; V2 is the discharge volume of the injection molding material from the second gate provided in a region other than the region (XA) where the composite material is disposed in the plan view of the cavity of the mold. For example, in the example shown in FIG. 31, three gates 613a are provided in the region Y1, six gates 613b are provided in the region XA, and two gates 613c are provided in the region Y2. At this time, if the total discharge volume of the injection molding material discharged from the gate 613b is V1 and the total discharge volume of the injection molding material discharged from the gates 613a and 613c is V2, it is preferable that 0 < V1 < V2 is satisfied. When 0 < V1 < V2 is satisfied, since the injection molding material ejected from gates 613a and 613c spreads to region XA where the composite material is disposed, it is possible to promote the injection molding material from entering between the composite material and the cavity wall surface of the second mold (preferably the movable mold).

[0109] 2.3 Flow holes When a design surface is formed by the first mold and the injection molding material is filled between the first mold and the composite material, for example, as shown in FIG. 26, at least one flow hole X1 through which the injection molding material passes through the composite material is provided. It is preferable that the injection molding material ejected from gate 413 of the first mold 410 flows through the flow hole X1 and is then ejected between the composite material and the second mold 420. By the injection molding material passing through the flow hole X1 from the first mold 410, the injection molding material can enter between the composite material and the second mold 420. At this time, it is preferable to provide a gate 413 in the region of the first mold 410 where the composite material is disposed.

[0110] <00,00601>2.4 Arrangement of resin sheet When the design surface is formed by the second mold, it is preferable to dispose a resin sheet between the composite material disposed in the first mold and the second mold. By disposing the resin sheet, it is easier to form a design surface on the molded body. It is preferable that the resin sheet does not contain fibers because the transferability of the mold mirror surface of the second mold is good. The resin sheet may be laminated with the composite material and then disposed in the first mold, or the resin sheet may be laminated on the composite material after the composite material is disposed in the first mold.

[0111] 2.5 Texturing When the design surface is formed by the second molding die, the design surface may have a textured pattern formed by the second molding die. By transferring the mold surface of the second molding die to create a textured pattern on the molded body, the reinforcing fibers contained in the composite material can be made less noticeable, improving the design. To make it easier for the mold surface of the second molding die to transfer the textured pattern to the composite material, a resin-rich layer may be provided on the surface of the composite material, or a resin sheet may be placed between the second molding die and the composite material when the composite material is placed in the first molding die.

[0112] This application is based on Japanese Patent Application No. 2022-149322 filed on September 20, 2022 and Japanese Patent Application No. 2022-196925 filed on December 9, 2022, the contents of which are incorporated herein by reference. [Explanation of symbols]

[0113] 1, 101, 201, 301, 501 Molded body 1H, 2H, 3H, 22, 101H, 102H, 103H, 201H, 202H, 203H, 222, 301H, 302H, 303H, 322, 422 holes 2 Reinforcement 2A, 102A, 202A, 302A, 402A, 502A, 602A Composite material 3 Main body 3B, 103B molding material 10, 210, 310, 410, 510, 610 First mold 11, 211, 311 cavities 12, 212, 312, 412, 512 Fixing member 20, 120, 220, 320, 420 Second mold 203B, 303B injection molding material 213, 323, 413, 613a, 613b, 613c Gates

Claims

1. A method for manufacturing a molded body integrally molded from a composite material containing reinforcing fibers dispersed in an in-plane direction and a molding material having a higher fluidity than the composite material, A method for producing a molded body, comprising the following steps (0) to (3): (0) heating the composite material and the molding material to a first predetermined temperature; (1) a step of fixing the composite material to a first molding die using a plurality of fixing members provided on the first molding die, the first molding die having a cavity with an area larger than that of the composite material in a plan view; (2) a step of moving a second molding die toward the composite material fixed to the first molding die and bringing the second molding die into contact with the composite material; (3) A step of pressing the composite material and the molding material together using the first molding die and the second molding die to form an integral molding.

2. The method for producing a molded article according to claim 1 , further comprising the step of releasing the composite material from the fixing member.

3. The method for producing a molded article according to claim 1 or 2, further comprising, before the step (1), a step of laminating the molding material onto the composite material.

4. The method for producing a molded article according to claim 3 , wherein in the step (1), the composite material is fixed to the first mold so that the molding material is in contact with the first mold.

5. The method for producing a molded body according to claim 1 or 2, wherein in step (1), the composite material is fixed to the first mold so that the molding material is positioned on an opposite side to the first mold.

6. The method for producing a molded article according to claim 1 or 2, further comprising the step of laminating the molding material onto the composite material after the step (1) and before the step (2).

7. 3. The method for producing a molded body according to claim 1, wherein the molding material is an injection molding material, and the method includes, after step (2) and before step (3), a step of injecting the molding material between the first mold and the second mold.

8. 3. The method for producing a molded body according to claim 2, wherein the molding material is an injection molding material, and the method includes a step of injecting the molding material between the first mold and the second mold after the step (2) and before the step of releasing the fixing of the composite material by the fixing member.

9. The method for producing a molded article according to claim 7 , wherein the molding material is injected between the first mold and the composite material.

10. The method for producing a molded article according to claim 7 , wherein the molding material is injected between the second mold and the composite material.

11. The method for manufacturing a molded article according to claim 1 or 2, wherein the first mold and the second mold are a pair of male and female molds.

12. The method for producing a molded article according to claim 11 , wherein the first mold is a fixed mold and the second mold is a movable mold.

13. The method for manufacturing a molded article according to claim 11 , wherein the first mold is a lower mold and the second mold is an upper mold.

14. The method for manufacturing a molded body according to claim 1 or 2, wherein the fixing member is a hole forming member that forms holes in the molded body.

15. The method for producing a molded article according to claim 1 or 2, wherein the reinforcing fibers are randomly dispersed in two-dimensional directions in the in-plane direction of the composite material.

16. A method for producing the molded article according to claim 12, the molding material is an injection molding material, and the method includes a step of injecting the injection molding material between the first mold and the second mold after the step (2) and before the step (3); Injection is performed from the first mold. A method for manufacturing a molded body.

17. A method for producing the molded article according to claim 16, a design surface is formed by the second molding die, and the injection molding material is filled between the second molding die and the composite material.

18. A method for producing the molded article according to claim 17, providing one or more flow holes in the composite material for the injection molding material to pass through; the injection molding material injected from the first mold flows through the flow holes and is injected between the first mold and the second mold; A method for manufacturing a molded body.

19. A method for producing the molded article according to claim 18, the first mold has a first gate, which is a gate for injecting an injection molding material into the mold, in a region where the composite material is placed in a plan view; A method for manufacturing a molded body.

20. A method for producing the molded article according to claim 16, A design surface is formed by the second molding die, and a resin sheet is placed between the second molding die and the composite material. A method for manufacturing a molded body.

21. A method for producing the molded article according to claim 17, The design surface has a grain pattern formed by the second molding die. A method for manufacturing a molded body.

22. the first mold is a fixed mold, and the second mold is a movable mold; A method for manufacturing a molded body by opening and closing the second mold by moving it horizontally, comprising: The method for producing a molded article according to claim 1 or 2, wherein there are at least two fixing members which are positioned at different heights.

23. the first mold is a fixed mold, and the second mold is a movable mold; A method for manufacturing a molded body by opening and closing the second mold by moving it horizontally, comprising: The method for producing a molded article according to claim 1 or 2, wherein there are at least two fixing members which are positioned at different horizontal positions.

24. The composite material has a pattern cut and cut shape. A method for producing the molded article according to claim 1 or 2.

25. A method for producing the molded article according to claim 19, a second gate for injecting the injection molding material in a region other than the region in which the composite material is placed in a plan view of the first molding die; the number n1 of the first gates and the number n2 of the second gates satisfy 0<n1<n2; A method for manufacturing a molded body.

26. A method for producing the molded article according to claim 19, the first molding die has a second gate for injecting the injection molding material in an area other than an area where the composite material is placed in a plan view; the discharge amount V1 of the injection molding material from the first gate and the discharge amount V2 of the injection molding material from the second gate satisfy the relationship 0<V1<V2; A method for manufacturing a molded body.

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