JP2005212383A - Resin transfer forming method and manufacturing method for sandwich laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin transfer forming method and a manufacturing method for a sandwich laminate which diffuse a resin efficiently and enable attainment of a article having a uniform resin thickness. <P>SOLUTION: A bagging film 12 is superposed on a fiber reinforcement 4 laid on a bottom force 2 and is sealed airtightly at the peripheral edge to the bottom force 2, and a gap between the bagging film 12 and the bottom force 2 is evacuated, while the resin is injected into the fiber reinforcement 4. In this resin transfer forming method, a resin injection path 8 and a resin discharge path 6 parallel to each other are provided alternately or separately between the bagging film 12 and the bottom force 2. The resin is injected from the resin injection path 8, while the gap between the bagging film 12 and the bottom force 2 is evacuated from the resin discharge path 6, and after the resin injected from the resin injection path 8 is transferred to the resin discharge path 6, the resin injection path 8 and the resin discharge path 6 are evacuated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides a resin injection path and a resin discharge path between the upper mold or the bagging film and the lower mold and moves the resin injected from the resin injection path to the resin discharge path to fill them, and then injects the resin. The present invention relates to a resin transfer molding method for obtaining a molded product having a uniform thickness after curing by discharging an excess resin from a channel and a resin discharging channel, and a method for manufacturing a sandwich laminate.

  The resin transfer molding method is a kind of molding method using a thermosetting resin, and is a molding method in which a molded product is obtained by injecting a resin into a mold cavity and curing it. As the mold for injecting the resin, a highly rigid mold is generally used. For the purpose of manufacturing a large molded product, molding is performed by replacing a part of the mold with a flexible bagging film.

  To form a composite material using the resin transfer molding method, after laying a molding material such as a fiber reinforcing material on the mold, the resin is injected into the cavity of the mold and the fiber reinforcing material is impregnated with the resin and cured. .

  For this reason, the resin is injected by a low-pressure encapsulating molding method using vacuum assist that does not apply excessive pressure to the mold or molded product and can shorten the resin injection time.

  In particular, when molding is performed with the mold and bagging film sealed, if the pressure between the mold and the bagging film is reduced, the bagging film adheres to the molding material and closes the resin flow path. Is disturbed.

  For this reason, when a composite material is manufactured using a bagging film, a resin diffusion base material (media) is usually used so that the resin is easily diffused. The resin diffusion base material is a mesh-like sheet, which is laid on the molding material after the molding material is laid on the mold.

  Further, in the molding of a sandwich plate using a core material, there is a resin transfer molding method (Patent Documents 1 and 2) in which grooves are provided on the surface of a core material made of a foamed material such as polyurethane or a balsa material. This method uses a plurality of parts coated with a fiber reinforcement on a core material having a groove network on the surface and arranges it in the shape of the desired molded product, and then supplies resin to the groove of the core material to produce a fiber reinforcement. It is impregnated and integrated to obtain a final molded product.

  Further, as another method, a method of performing groove processing on a mold such as a metal mold or FRP mold is also disclosed (Patent Document 3).

  As described above, in order to efficiently diffuse the resin, a resin diffusion base material, a core material such as a foam having a groove on the surface, and the like are conventionally used.

JP 2000-501659 A (page 21, FIG. 1) JP-T-2001-510748 (page 11, paragraph number (0017)) JP 2001-62932 A (FIG. 2)

  In general, when a resin is injected under vacuum, as the resin impregnates the fiber reinforcement, the degree of vacuum between the bagging film or the upper mold and the lower mold is not uniform, and the degree of vacuum decreases as the distance from the exhaust port increases. . The degree of vacuum in the vicinity of the resin injection port located farthest from the exhaust port is different from that in the vicinity of the exhaust port, and the thickness of the molded product after curing is different. That is, the thickness of the molded product tends to be thin near the exhaust port, and the molded product tends to be thick near the resin injection port.

  An object of the present invention is to provide a resin transfer molding method and a sandwich laminate manufacturing method in which a molded article having a uniform thickness after curing can be obtained even if a resin is injected between a bagging film or an upper die and a lower die under vacuum. It is to provide.

  The present invention for solving the above problems is described below.

  [1] A bagging film or upper mold is overlapped on a fiber reinforcing material laid on the lower mold, and the periphery of the bagging film is hermetically sealed to the lower mold, or the upper mold and the lower mold are clamped, and the bagging film or upper mold is sealed. In a resin transfer molding method in which a resin is injected into a fiber reinforcement and cured between the upper mold and the lower mold, a resin injection path and a resin discharge path parallel to each other are provided between the bagging film or the upper mold and the lower mold. After injecting the resin from the resin injection path alternately or one by one and exhausting the bagging film or between the upper mold and the lower mold from the resin discharge path and filling the resin from the resin injection path to the resin discharge path A resin transfer molding method characterized in that the resin is cured while being discharged from a resin injection path and a resin discharge path.

  [2] The resin transfer molding method according to [1], wherein a distance between the resin injection path and the resin discharge path is 200 cm or less.

  [3] The degree of vacuum at the time of resin injection between the bagging film or the upper mold and the lower mold is −0.10 to −0.08 MPa, and the degree of vacuum at the time of curing the resin is −0.08 to −0. The resin transfer molding method according to [1] or [2], which is 0.02 MPa.

  [4] The resin transfer molding method according to any one of [1] to [3], wherein the viscosity of the resin at the time of injection is 0.01 to 1 Pa · s.

  [5] A fiber reinforcing material, a core material, and a fiber reinforcing material are sequentially stacked on one surface of the lower die, and a bagging film or an upper die is stacked on these to seal the bagging film periphery hermetically to the lower die. Alternatively, in the sandwich laminate manufacturing method in which the lower mold and the upper mold are clamped, the bagging film or the space between the upper mold and the lower mold is evacuated, and the resin is injected into the fiber reinforcing material to be cured. A resin injection path and a resin discharge path parallel to each other are provided between the mold and the lower mold to inject the resin from the resin injection path and to discharge the resin between the bagging film or the upper mold and the lower mold. A method for producing a sandwich laminate, comprising: exhausting from a path to fill a resin from a resin injection path to a resin discharge path, and curing the resin while discharging the resin from the resin injection path and the resin discharge path.

  [6] The method for manufacturing a sandwich laminate plate according to [5], wherein the distance between the resin injection path and the resin discharge path is 200 cm or less.

  [7] The degree of vacuum at the time of resin injection between the bagging film or the upper mold and the lower mold is −0.10 to −0.08 MPa, and the degree of vacuum at the time of curing the resin is −0.08 to −0. The method for producing a sandwich laminate according to [5] or [6], which is 0.02 MPa.

  [8] The method for producing a sandwich laminate according to any one of [5] to [7], wherein the viscosity of the resin at the time of pouring is 0.01 to 1 Pa · s.

  In the resin transfer molding method of the present invention, the resin injection path and the resin discharge path are provided between the upper mold or the bagging film and the lower mold, and the resin injected from the resin injection path is moved to the resin discharge path, and then the resin injection Since the resin is cured while discharging excess resin from the path and the resin discharge path, a molded product having a uniform thickness after curing can be obtained.

  Hereinafter, the resin transfer molding method of the present invention will be described with reference to FIGS.

  First, a fiber reinforcing material 4 and a resin diffusion base material (media) 5 are laid in order on a mold 2 subjected to a release treatment using a known release agent such as silicone oil (FIG. 1A).

  Next, two tubes 6 and 8 are arranged in parallel to each other on both sides of the laid fiber reinforcement 4. Next, the bagging film 12 is placed over the resin diffusion base material 5, and the periphery of the bagging film 12 is hermetically sealed with the mold 2 using the sealant 14. The sealant and the sealing method using the sealant are known. The tubes 6 and 8 have holes for injecting resin into the fiber reinforcement 4 or exhausting the space between the mold and the bagging film (exhausting the resin).

  FIG. 2 shows a plan view of the state where the bagging film of FIG. One end of the tube 6 (resin discharge path) forms a resin discharge port 6a, and both ends of the tube 8 (resin injection path) form a resin injection port 8b and a resin discharge port 8a. The resin injection port 8b and the resin discharge port 8a have means (valves 10a and 10b) for controlling the injection or discharge of the resin, respectively, and the resin discharge ports 6a and 8a are connected to a vacuum pump (not shown). .

  Thereafter, the vacuum pump connected to the resin discharge ports 6a and 8a is operated, and the gas between the mold 2 and the bagging film 12 is exhausted from the tube 6 with the valves 10a and 10b closed to reduce the pressure (FIG. 1 (b )).

  Further, in a state where the space between the mold 2 and the bagging film 12 is exhausted from the tube 6, the valve 10 b is opened, and the resin is injected between the mold 2 and the bagging film 12 through the tube 8 from the resin injection port 8 b. Since the resin injected from the tube 8 is exhausted from the tube 6 located on the other end side of the mold 2, the resin is impregnated into the fiber reinforcement 4 while being pressed against the bagging film 12 and moves toward the tube 6.

  After the resin fills the tube 8 and the fiber reinforcing material 4 and moves to the tube 6, the valve 10b is closed, the valve 10a is opened, and the exhaust is performed from the resin discharge port 8a in addition to the resin discharge port 6a. Therefore, excess resin near the resin injection path is discharged to the outside.

  The resin impregnated in the fiber reinforcement 4 is cured while exhausting excess resin from the resin discharge ports 6a and 8a to the outside (FIG. 1 (c)). When heating is required for curing the resin, the fiber reinforcement 4 injected with the resin is heated together with the mold 2 and the bagging film 12 using an oven or the like. The obtained molded product is composed of a fiber reinforced plastic layer 16 in which a fiber reinforcing material is impregnated with a resin and cured, a resin covering the surface thereof, and a layer 18 in which the resin diffusion base material 5 is cured. Even when the injected resin is cured, it is preferable to exhaust the gas between the mold 2 and the bagging film 12.

  In the present invention, the distance between the resin injection path 8 and the resin discharge path 6 is preferably 200 cm or less, and more preferably 50 to 200 cm. If the interval is less than 50 cm, a lot of resin injection paths and resin discharge paths will be disposed, so that a lot of resin is wasted. If it exceeds 200 cm, the degree of vacuum between the resin injection port and the resin discharge port can be different, and after curing, The thickness of the molded product tends to be different. For example, if the distance between the resin injection path 8 and the resin discharge path 6 exceeds 200 cm, the molded product farthest from the discharge port can be removed even if the valve 10a is opened in addition to the resin discharge port 6a and the resin discharge port 8a is discharged. Excess resin in the central portion cannot be discharged to the outside, and a molded product with a thick central portion tends to be formed.

  The exhaust between the mold 2 and the bagging film 12 is preferably performed so that the degree of vacuum between the bagging film and the lower mold is −0.10 to −0.08 MPa when the resin is injected, and the degree of vacuum is set when the resin is cured. It is preferable to carry out so as to be −0.08 to −0.02 MPa.

  The resin diffusion base material 5 is not necessarily used, but is desirably used in order to increase the resin diffusion rate. When removing the resin diffusion base material from the molded product, a peel cloth or the like may be laid between the fiber reinforcement 4 and the resin diffusion base material 5 as necessary.

  1 shows the case where one resin injection path and one resin discharge path are arranged, a plurality of resin injection paths and resin discharge paths may be alternately arranged in parallel with each other. When arranging a plurality of resin injection paths and resin discharge paths, the interval is preferably 200 cm or less.

  In FIG. 1, a perforated tube is used as the resin injection path and the resin discharge path. However, the resin injection path and the resin discharge path can secure a resin flow path when the bagging film is deformed by exhaust. Any shape and material can be used. Specific examples include a perforated tube, a spring-like tube, a columnar structure such as an I-type or an L-type, a rod-like body having protrusions, and the like.

  In the present invention, it is preferable to use a perforated tube or a spring-like tube having a diameter of 3 to 20 mm as the resin injection path or the resin discharge path. Spring-like tubes are most preferred because they are easy to adjust in length and conform to the molding surface.

  Further, grooves formed in a mold or a rubber sheet (which acts as a bagging film) may be used as the resin injection path and the resin discharge path. FIG. 3 shows an example in which the groove 70 formed in the mold 19 is a resin injection path and the groove 72 is a resin discharge path. As the material of the mold 19, rubber, FRP or the like can be used.

  In the present invention, in order to increase the diffusion rate of the resin, a groove (resin diffusion groove) for diffusing the resin from the resin injection path to the resin discharge path is formed instead of the resin diffusion base material or together with the resin diffusion base material. A mold, rubber sheet or plate may be used.

  FIG. 4 shows a plan view of a mold 51 in which a resin diffusion groove 54 is formed between a resin injection groove 50 and a resin discharge groove 52 as an example of a mold in which a resin diffusion groove is formed. Further, as in the mold 66 shown in FIG. 5, the resin diffusion groove 64 may not be continuously connected between the resin injection groove 60 and the resin discharge groove 62.

  The fiber reinforcing material 4 is sealed between the mold 2 in which the resin diffusion groove 20 is formed and the bagging film 12 and the rubber reinforcing material 4 is sealed between the mold 2 and the rubber sheet 21 in which the resin diffusion groove 22 is formed. FIGS. 6 and 7 show examples of the state where the seal is sealed, respectively.

The groove formed in the mold or rubber sheet as the resin diffusion groove is not particularly limited as long as it becomes a resin flow path, but the width is 0.5 to 5 mm, the depth is 1 to 5 mm, and the cross section is perpendicular to the length direction. The cross-sectional area is preferably 0.5 to 25 mm ² . If the cross-sectional area is less than 0.5 mm ² , the diffusion rate of the resin tends to be slow, and if it exceeds 25 mm ² , the amount of resin that is not used tends to increase and it becomes uneconomical.

  The shape of the groove having a cross section perpendicular to the length direction is not particularly limited, and may be an arbitrary shape such as a U shape, a V shape, a semicircle, or a polygon.

  The interval between the resin diffusion grooves is preferably 20 to 200 mm. If the interval is less than 20 mm, a lot of the resin is wasted, and if it exceeds 200 mm, the resin impregnation speed to the fiber reinforcement is slow, and an unimpregnated portion tends to occur.

  As a method of forming grooves in the rubber sheet, for example, a method of performing groove processing on a rubber sheet having a thickness of about 2 to 10 mm, a method of pouring unvulcanized rubber into a mold having protrusions, and then vulcanizing, a non-vulcanized rubber Examples thereof include a method of vulcanizing after placing the sheet on a mold having protrusions.

  As the material of the rubber sheet forming the groove, any known material can be used as long as it can form the groove. For example, silicone rubber, fluorine rubber, urethane rubber, natural rubber, butadiene rubber, acrylic rubber, nitrile rubber, etc. Can be mentioned.

  When forming the groove, the rubber sheet preferably has a hardness (conforming to JIS K 6301) of 25-80.

  The shape of the rubber sheet produced by vulcanizing the unvulcanized rubber is not particularly limited and can be appropriately selected depending on the shape of the target molded product, etc., but it is preferable to use one having a thickness of 2 to 10 mm.

  Further, the resin diffusion groove may be formed by inserting a plate in which a groove is formed between the bagging film and the mold. FIG. 8 shows an example in which a plate 30 having a resin diffusion groove 24 formed between the fiber reinforcement 4 laid on the mold 2 and the bagging film 12 is inserted. As the plate, a rubber sheet in which the groove is formed, an FRP plate having a thickness of 1 to 5 mmt, a metal plate, or the like can be used.

  In the present invention, different forms of resin diffusion grooves may be used in combination.

  In the above description, a case where molding is performed using a mold and a bagging film or a rubber sheet is shown, but a split mold may be used in the present invention. An example in the case of using the split type is shown in FIG.

  After the fiber reinforcing material 4 is laid on the lower die 36, the upper die 42 having the resin diffusion groove 38 is overlapped and clamped, and the upper die 42 and the lower die 36 are sealed with an O-ring 44. Then, it shape | molds like the case where a bagging film is used.

  The resin diffusion groove may be formed in the lower mold, or a plate in which the groove shown in FIG. 8 is formed may be inserted.

  The material of the split mold is not particularly limited, and for example, an FRP mold or a mold can be used.

  As the fiber reinforcing material used in the present invention, materials used for ordinary fiber reinforcing materials such as carbon fiber, glass fiber, aramid fiber, boron fiber, and metal fiber can be used. Among these, carbon fiber, glass fiber, and aramid fiber are preferable.

  The form of the fiber reinforcement is not particularly limited, and woven fabrics, knitted fabrics, nonwoven fabrics, and the like can be used.

  When weaving is used as the fiber reinforcing material, any woven type may be used, but the material itself is plane symmetric, or a plurality of fiber reinforcing materials are combined in a plane symmetric manner and stacked. It is preferable to use it. By using a plane symmetric fiber reinforcement or a piled and plane symmetric fiber reinforcement, it is possible to prevent warping of the molded product when formed into a molded product.

  Examples of the plane-symmetric fabric or the fabric that can be stacked to be plane-symmetric include a unidirectional fabric and a multiaxial fabric.

  The unidirectional woven fabric refers to a woven fabric in which bundles of fiber reinforcing materials arranged in parallel are knitted with nylon yarn, polyester yarn, glass fiber yarn or the like. A polyaxial woven fabric refers to a woven fabric in which bundles of fiber reinforcements aligned in one direction are formed in a sheet shape and laminated at different angles and stitched with nylon yarn, polyester yarn, glass fiber yarn or the like.

  Examples of preferred multiaxial fabrics include [0 / -45 / -45 / 0], [0 / + 45 / -45 / -45 / + 45/0], [0 / + 45/90 / -45 / -45 / 90 / + 45/0]. For example, [0 / −45] and [−45/0], [0 / + 45 / −45] and [−45 / + 45/0], [0 / + 45 / −45 / 90] and [90 / −45 / + 45/0] can be exemplified. 0, ± 45, 90 represents the lamination angle of each layer constituting the multiaxial woven fabric, and the fiber axis direction of the fiber reinforcing material aligned in one direction is 0 °, ± 45 ° with respect to the length direction of the woven fabric. , 90 °. The stacking angle is not limited to these angles, and can be any angle.

  The thickness of the multiaxial woven fabric is appropriately selected depending on the application of the molded product, but is usually preferably 0.2 to 3 mm.

Basis weight of the fibrous reinforcement is preferably one per ^{200~4000g / m 2, 400~2000g / m} 2 is more preferable.

  As the resin used in the resin transfer molding method of the present invention, a thermosetting resin usually used for the production of a molded product can be used. Specifically, epoxy resin, unsaturated polyester resin, phenol resin, melamine resin, polyurethane resin, silicon resin, maleimide resin, vinyl ester resin, cyanate ester resin, resin obtained by prepolymerizing maleimide resin and cyanate ester resin, etc. In the present invention, a mixture of these resins can also be used. When a fiber reinforced composite material is used, an epoxy resin composition and a vinyl ester resin composition excellent in heat resistance, elastic modulus, and chemical resistance are preferable. These thermosetting resins may contain a colorant, various additives and the like in addition to the curing agent and the curing accelerator.

  The thermosetting resin preferably has a viscosity at the time of injection of 0.01 to 1 Pa · s by heating or the like.

  Next, a method for manufacturing the sandwich laminate of the present invention will be described with reference to FIG.

  A fiber reinforcing material 4a, a core material 5, and a fiber reinforcing material 4b are sequentially stacked on the mold 2 subjected to the mold release treatment. Thereafter, after the tubes 6 (resin discharge path) and 8 (resin injection path) are arranged, the laminated material is sealed with the bagging film 12, and a sandwich laminate is produced in the same manner as in the resin transfer molding method described above.

  The resin injection path and the resin discharge path can have the same form as the above-described resin transfer molding method. Further, it is preferable to form a resin diffusion groove in the core material 5.

  Examples of the core material include urethane foam, vinyl chloride foam, polymethacrylimide foam, acrylic foam, phenol foam, and polystyrene foam. Balsa wood can also be used.

  The thickness of the core material is appropriately selected depending on the use of the sandwich laminate, but is usually preferably 3 to 200 mm.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Example 10 pieces of carbon fiber woven fabric W-3101 manufactured by Toho Tenax Co., Ltd. cut to a width of 50 cm and a length of 150 cm were laminated on a release-treated aluminum plate. On top of that, peel cloth Release Ply C (manufactured by AIRTECH) and resin diffusion base material Resin Flow 60 (manufactured by AIRTECH) were laminated. After that, two φ10mm spiral (spring-like) tubes are placed in the length direction of the carbon fiber fabric as sealant tape, resin injection path and resin discharge path on the aluminum plate, and further for forming the resin injection port and resin discharge port A hose was placed at each end of the spring-like tube. The carbon fiber fabric laminated with the bagging film and the tube were covered, and the whole except the resin inlet and the resin outlet was sealed with a sealant tape. Thereafter, both ends (resin injection port and resin discharge port) of the resin injection φ12 mm hose are closed, and the inside of the bagging film is set to −0.1 MPa by a vacuum pump from the resin discharge port formed on one end side of the resin discharge φ12 mm hose. The pressure was reduced. Next, 100 parts by mass of Lipoxy R-806 (manufactured by Showa Polymer Co., Ltd.), 1.0 part by mass of Permeric N (manufactured by Nippon Oil & Fats Co., Ltd.), and 0.5 part by mass of 6% cobalt naphthenate (manufactured by Kanto Chemical Co., Inc.) The mixed liquid mixture was injected into the carbon fiber fabric from a resin injection port formed at one end of a φ12 mm hose for resin injection at a vacuum degree of −0.1 MPa in an atmosphere of 25 ° C. After resin injection, the degree of vacuum is adjusted to -0.05 MPa, the resin injection port is closed, the resin discharge port formed on the other end of the resin injection hose is opened, and the degree of vacuum is also from the discharge port of the resin injection hose- Reduced pressure at 0.05 MPa and cured.

  The obtained molded product (practical product) had little variation in plate thickness.

Comparative Example A molded product (comparative product) was obtained in the same manner as in the example except that the resin was discharged only from the resin discharge hose and the resin was not discharged from the resin injection hose.

  Table 1 shows the results of measurement of the plate thickness in the vicinity of the resin injection path, the central portion, and the vicinity of the resin discharge path of the implemented product and the comparative product.

Table 1
─────────────────────────
Product Comparison product ─────────────────────────
Near the resin injection path 2.1 2.1
Center 2.1 2.1
Near resin discharge path 2.1 2.4-2.5
─────────────────────────
(Unit: mmt)

It is a flowchart which shows an example of the resin transfer molding method of this invention, (a) is sectional drawing which shows the state which sealed the fiber reinforcement material between the bagging film and the type | mold, (b) is between a bagging film and a type | mold. Sectional drawing which shows the state which reduced pressure, (c) is sectional drawing which shows the state which made the fiber reinforcement material impregnate resin. It is a top view which shows the state which removed the bagging film of Fig.1 (a). It is sectional drawing which is another example of the resin transfer molding method of this invention, Comprising: The groove | channel formed in the type | mold is used as the resin injection path and the resin discharge path. It is a top view which shows an example of the type | mold which formed the groove | channel for resin diffusion used for this invention. It is a top view which shows the other example of the type | mold which formed the groove | channel for resin diffusion used for this invention. It is sectional drawing which is another example of the resin transfer molding method of this invention, Comprising: The example which formed the groove | channel on one surface of a type | mold. It is sectional drawing which is another example of the resin transfer molding method of this invention, Comprising: The example which formed the groove | channel in the rubber sheet. It is sectional drawing which is another example of the resin transfer molding method of this invention, Comprising: The example which has arrange | positioned the plate in which the groove | channel was formed. It is sectional drawing which is another example of the resin transfer molding method of this invention, Comprising: The example which formed the groove | channel in the split type upper mold | type. It is sectional drawing which shows an example of the manufacturing method of the sandwich laminated board of this invention.

Explanation of symbols

Type 2 4 Fiber reinforcement 5 Resin diffusion base material (media)
6, 8 Tube 10 Valve 12 Bagging film 14 Sealant 16 Resin impregnated layer 18 Resin layer 6a, 8a Resin outlet 8b Resin inlet

Claims (8)

A bagging film or upper mold is overlapped on the fiber reinforcement laid in the lower mold, and the periphery of the bagging film is hermetically sealed to the lower mold, or the upper mold and the lower mold are clamped, and the bagging film or the upper mold and the lower mold are sealed. In a resin transfer molding method in which a resin is injected into a fiber reinforcement and cured by resin, a bagging film or a resin injection path and a resin discharge path that are parallel to each other between an upper mold and a lower mold are alternately or Resin is injected from the resin injection path by filling the resin from the resin injection path by exhausting the bagging film or between the upper mold and the lower mold from the resin discharge path. A resin transfer molding method characterized in that the resin is cured while being discharged from a path and a resin discharge path. The resin transfer molding method according to claim 1, wherein the distance between the resin injection path and the resin discharge path is 200 cm or less. The degree of vacuum when injecting the resin between the bagging film or the upper mold and the lower mold is -0.10 to -0.08 MPa, and the degree of vacuum when curing the resin is -0.08 to -0.02 MPa. The resin transfer molding method according to claim 1 or 2. The resin transfer molding method according to any one of claims 1 to 3, wherein the viscosity of the resin at the time of injection is 0.01 to 1 Pa · s. A fiber reinforcing material, a core material, and a fiber reinforcing material are sequentially stacked on one surface of the lower mold, and a bagging film or an upper mold is layered on these layers, and the periphery of the bagging film is hermetically sealed to the lower mold or the lower mold. In the method for manufacturing a sandwich laminate in which a bagging film or an upper mold and a lower mold are evacuated and a resin is injected into a fiber reinforcement and cured, the bagging film or the upper mold and the lower mold are clamped. A resin injection path and a resin discharge path that are parallel to each other are provided between the mold and one by one to inject the resin from the resin injection path and exhaust the bagging film or between the upper mold and the lower mold from the resin discharge path. Then, after the resin is filled from the resin injection path to the resin discharge path, the resin is cured while being discharged from the resin injection path and the resin discharge path. 6. The method for producing a sandwich laminate according to claim 5, wherein the distance between the resin injection path and the resin discharge path is 200 cm or less. The degree of vacuum when injecting the resin between the bagging film or the upper mold and the lower mold is -0.10 to -0.08 MPa, and the degree of vacuum when curing the resin is -0.08 to -0.02 MPa. A method for producing a sandwich laminate according to claim 5 or 6. The method for producing a sandwich laminate according to any one of claims 5 to 7, wherein the viscosity of the resin at the time of pouring is 0.01 to 1 Pa · s.

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