JP2005288785A - Method for producing preform - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a preform which eliminates a thermal crack, fiber damage, and R-shaped out-of-plane wrinkles and does not spoil the physical properties or surface quality of a large-sized composite material molding by simple equipment. <P>SOLUTION: The method for forming the preform having a desired shape from a fiber laminate includes a fiber laminate setting process (A) in which a tool or a core material is set on a mold surface, and the fiber laminate made of a reinforcing fiber substrate is arranged on it, a sheet setting process (B) in which the fiber laminate is covered with a sheet, and part of the sheet is adhered to a mold while the sheet is not adhered to a corner part formed by the tool or the core material and the mold, and a surface pressure application process (C) in which surface pressure is applied at least one part of the sheet. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a fiber laminate (hereinafter simply referred to as a preform) used when a structure made of reinforced fiber plastic (hereinafter simply referred to as FRP) is manufactured by the Resin Transfer Molding method (hereinafter simply referred to as RTM method). )). Specifically, for example, a manufacturing method of a preform used for forming a stringer or a rib of an aircraft wing which is a reinforcing member of an FRP skin panel which is a structural member of an aircraft, a ship, an automobile member, a stiffener or a rib for reinforcing a ship bottom. The present invention relates to a manufacturing method capable of realizing improvement in dimensional accuracy, improvement in surface quality, and the like.

  Conventionally, in the molding method of composite material structural members such as FRP panels, girders, etc. used as structural members such as aircrafts, ships, and building members, and outer panels for automobiles, the RTM method is productivity and manufacturing cost. In recent years, it is widely adopted because of its superiority, and the fiber laminate to be molded in the resin injection process is sealed with a bag material, and the matrix resin is injected in a vacuum suction state, so-called Vacuum-Assisted Resin Transfer Molding (Vacuum RTM) The molding method has become mainstream.

  At that time, in order to uniformly inject the matrix resin into every corner of the reinforcing fiber of the fiber laminate, in consideration of the final product shape of the fiber laminate formed by laminating a plurality of reinforcing fiber base materials, A so-called preform process is required, which is shaped into a shape.

  This process is complicated and difficult to perform lamination, cutting and shape fixing of preforms, and uneven distribution of reinforcing fibers tends to occur in the obtained preforms, making it impossible to produce homogeneous products. As a result, the appearance of molded products He had problems such as poor quality and insufficient strength.

  In order to simplify the process of stacking, cutting, and fixing the shape of a preform, a base material provided with a resin that improves handling properties such as tackiness has been proposed. Since this base material does not stick between layers at the time of lamination as in the case of a prepreg, the deformability is extremely high, and after a thick material is laminated at one time, it can be bent at once and has the advantage of reducing man-hours over the prepreg. When producing a preform using the base material, the base material is laminated on a shaping jig or a core material (core material), the fiber laminate is heated along the core material, and a tacky resin is added. A process of softening and bonding the substrates is performed. This base material is a base material before resin impregnation, and the tacky resin softens during heat fixation, and the bulk of the fiber laminate is changed.

  For example, when the core material has a bent shape, a circumferential length difference occurs in the bent portion with a change in volume during heating and fixing. Therefore, it is necessary to manufacture in consideration of the circumference difference. However, there has been no technology for providing a preform that eliminates wrinkles and sagging caused by bulk changes.

  On the other hand, as a conventional technique for producing an R shape with a three-dimensional preform, a method has been proposed in which a fiber laminate that has been laminated in advance is bent into a predetermined R shape, and stitched and fixed by stitching (for example, Patent Document 1). reference). However, this method produces an out-of-plane wrinkle at the R portion when viewed microscopically, and when the stitching is performed, peripheral fiber breakage or local fiber bending through which the stitching fibers have passed occurs, and the molded product There were strength problems such as a decrease in strength and a resin-rich layer at the bent portion as the starting point of thermal cracks.

  Also, a method of obtaining a predetermined preform by laminating an x-yarn layer, a y-yarn layer, and a bias layer with a single stroke on a three-dimensional shape mold having a guide pin, bonding each layer with a z-yarn, and then demolding Has been proposed (see, for example, Patent Document 2). However, this method also causes the z-thread to locally bend the surrounding fibers, resulting in a decrease in the strength of the molded product, and when shaping a large surface area such as a long stringer, it is shaped through a guide pin with a single stroke. For this reason, the process time becomes long, and a machine for arranging yarns as equipment is required, which increases the cost.

  Also proposed is a method of making a preform with a predetermined shape by placing a fiber laminate on a female jig, fixing reinforcing fibers around the inside of the female mold, and pushing a male jig having an R shape into the female mold. (For example, see Patent Document 3). However, even in this method, when the male mold matches the predetermined preform shape, the base material is displaced when the male mold is pushed into the female mold, and the thickness of the fiber laminate changes due to the pressing pressure, thereby causing wrinkles. In addition, since a double-sided mold is required, when molding a large molded product such as an aircraft main wing member, there is a problem in that the cost of the mold equipment is increased.

Furthermore, in the prepreg molding, a core material having a desired shape is placed on the mold surface, and the FRP prepreg and the rubber sheet are sequentially evacuated so as to cover the core material, thereby closely attaching the FRP prepreg to the core material. A method for obtaining an FRP solid molded product having a shape matching the core material has been proposed (see, for example, Patent Document 4). However, this method also includes a method in which a jig having a constant height or a variable height is disposed between the end portion of the FRP prepreg and the rubber sheet, and the FRP is three-dimensionally formed by evacuation. However, when a jig with a certain height or a variable height jig is used, it is necessary to control the timing at which the rubber sheet comes into close contact with the tool surface, and it is necessary to prepare a jig with a different height for each shape. In addition, when using a base material to which particulate resin resin that improves handling properties such as tackiness is used, out-of-plane wrinkles caused by a difference in circumference at the R-shaped portion of the laminate of the base material in the heating step are eliminated. Such an effect cannot always be exhibited.
JP-A-11-269755 (Claim 1) JP-A-9-137336 JP-A-6-155383 (Claim 1) Japanese Patent Laid-Open No. 7-60770 (Claim 1, Example 1)

  The object of the present invention is to eliminate thermal cracks, fiber damage, and R-shaped out-of-plane wrinkles, which are the above-mentioned problems of the prior art, and prevent damage to physical properties and surface quality of large composite molded products with simple equipment. An object of the present invention is to provide a preform manufacturing method capable of obtaining a reform.

In order to achieve the above object, the present invention adopts the following configuration. That is,
(1) A method for producing a preform, wherein a preform having a desired shape is formed from a fiber laminate, and the preforms are sequentially subjected to at least the following steps (A) to (C).

      (A) A step of setting a fiber laminate in which a jig or a core material is installed on the mold surface, and a fiber laminate made of a reinforcing fiber substrate is arranged thereon.

      (B) The fiber laminate is covered with a sheet, and a part of the sheet is brought into close contact with the forming die in a state where the sheet is not brought into close contact with a corner portion formed by the jig or the core material and the forming die. Sheet setting process.

      (C) A surface pressure applying step of applying a surface pressure to at least a part of the sheet.

  (2) The method for producing a preform as described in (1) above, wherein as the fiber laminate, a particulate resin, a fibrous resin, or a film-like resin is used.

  (3) The method for producing a preform according to (1) or (2), wherein the sheet has an elongation in a range of 0.002 to 10%.

  (4) The method for producing a preform according to any one of (1) to (3), wherein the sheet has a releasability with respect to the fiber laminate.

  (5) In the said surface pressure addition process, the surface pressure of 30 kPa-500 kPa is provided, The manufacturing method of the preform in any one of said (1)-(4) characterized by the above-mentioned.

  (6) The preform according to any one of (1) to (5), wherein at least the following method (a) or (b) is used as a method for applying a surface pressure in the surface pressure applying step: Production method.

      (A) A method in which the entire mold surface is covered with a bag material and the periphery is sealed, and then the closed space formed by the mold and the bag material is sucked into a reduced-pressure atmosphere.

      (B) A method in which a bag containing liquid or gas is disposed on at least a part of a sheet surface placed on the mold surface together with the support structure of the bag, and the liquid or gas in the bag is pressurized and pressurized.

  (7) In any of the above (1) to (6), the entire temperature including at least the fiber laminate is heated in a range of 50 ° C. to 130 ° C. in the surface pressure applying step. A method for producing the preform as described.

  (8) In the step of setting the fiber laminate, an apparatus for raising and lowering the jig or the core material is installed on the mold, and in the surface pressure applying process, the jig or the core material is formed with the mold and the jig or The preform manufacturing method according to any one of (1) to (7), wherein the operation is performed so that the sheet can be raised and lowered within a range in which the sheet is not in close contact with the corner portion formed of the core material.

  By adopting the above configuration, the present invention can obtain a preform excellent in surface properties such as wrinkles and undulations using a fiber laminate with simple equipment. Moreover, it becomes possible to manufacture a preform without causing fiber damage, thermal cracks, and the like that cause a decrease in strength.

Hereinafter, the best mode for carrying out the production method of the present invention will be described in the order of each step with reference to the drawings.
1. (A) Setting process of fiber laminate FIG. 1 is a cross-sectional view for explaining a process of setting reinforcing fibers on a jig or a core material on a mold. In the figure, 1 is a molding die on a plane, and 2 is a core material such as a jig or foam fixed on the mold. The mold 1 and the convex jig 2 are preferably made of metal, synthetic resin, GFRP, or CFRP, which is a material that is not plastically deformed by the surface pressure applied in the surface pressure applying step described later. In addition, the mold 1 and the convex jig 2 are preferably those having releasability or imparting releasability to the fiber laminate 3. The core material 2 is preferably made of urethane resin, polyvinyl chloride, polyimide resin, acrylic resin, or FRP, but is not limited thereto.

  Reference numeral 3 denotes a fiber laminated body for eliminating wrinkles at a corner portion at a predetermined position on the jig or the foam, and a plurality of reinforcing fibers 4 are laminated.

The reinforcing fiber 4 used in the present invention is preferably carbon fiber, aramid fiber, or glass fiber. However, the reinforcing fiber may have various forms depending on the use of the woven fabric, unidirectional substrate, etc. The same applies to various characteristic values such as basis weight, fiber fineness, and elastic modulus. In addition, in order to join a plurality of reinforcing fibers 4 and integrate them as a fiber laminate 3, particulate resin, fibrous resin, or film-like resin that improves handling properties such as tackiness adheres between the reinforcing fiber layers. It is desirable that Examples of the adhesion method include application by spraying, entanglement between the fibrous resin and the reinforcing fiber, and stitching of fibers such as static electricity.
2. (B) Sheet Setting Step FIG. 2 is a cross-sectional view of a sheet setting step for covering the sheet 5 from above the fiber laminate 3. Next, as shown in the figure, the entire fiber laminate 3 is further covered with the sheet 5 from above, and a part of the sheet 5, for example, both end portions of the sheet are brought into close contact with the mold. The purpose of covering with the sheet 5 is to eliminate wrinkles at the corners of the fiber laminate 3 and to smooth the surface. In this setting step, it is preferable to cover the sheet 5 so as not to adhere to the corner portion 6 (see FIG. 3) formed by the convex jig or core material 2 and the mold 1. The reason is that, in the next surface pressure applying step, a space is required for the sheet 5 to move in the mold direction when a surface pressure is applied to the sheet 5. Therefore, the contact point between the outer periphery of the sheet 5 and the mold 1 is preferably located at a position away from the outer periphery of the convex jig 2 as shown in the cross-sectional view of FIG. That is, it is preferable to fix the sheet end so that the sheet 5 does not adhere to the corner 6 formed by the convex jig or core material 2 and the mold 1. Specific methods include sheet fixing using adhesive force such as a tape, pinching with a magnet, sheet fixing for mechanically applying surface pressure, sheet fixing for inserting a pin, etc., and fixing a magnetic sheet and a mold by magnetic force. Etc., and combinations thereof.

  The sheet used in this step has releasability from the particulate resin and sliding with the fiber laminate, and is applied to the corner portion of the core material 2 even when the surface pressure described in the next step is applied. What does not adhere | attach, ie, the thing which does not have a stretching property, is preferable. As the elongation, it is preferable to use a material in the range of 0.002 to 10%. As the material, glass cloth, aramid cloth, SUS, etc. coated with fluororesin are used for elongation, tensile strength, bending. Rigidity etc. are preferred.

As the sheet releasability, it is preferable that the surface of the sheet is coated with a fluorine resin such as PTFE, FEP, AFP, ETFE or the like as a coating material. A paraffin release material may be used.
3. (C) Surface pressure addition process Next, as shown in FIG. 3, the surface pressure 7 shown by the arrow of a figure is applied to at least one part from the top of the sheet | seat 5 to a fiber laminated body direction. In this case, the surface pressure is preferably about 30 kPa to 500 kPa. If the surface pressure is less than 30 kPa, the fiber laminate is not sufficiently pressed down, so that it tends to wrinkle in the molding process. There is a tendency not to have.

  As a specific surface pressure applying method, any of the following methods (a) or (b) may be used.

  (A) A method in which the entire mold surface is covered with a bag material, the periphery is sealed, and a closed space formed by the mold and the bag material is sucked into a reduced pressure atmosphere.

  (B) A method in which a bag containing liquid or gas is disposed on at least a part of the sheet surface placed on the mold surface together with the support structure of the bag, and the liquid or gas in the bag is pressurized and pressurized.

  Moreover, it is good to heat the whole temperature including a fiber laminated body in the range of 50 to 130 degreeC in the case of the pressurization by these methods. The reason for this is that the fiber laminate can be maintained in a state where the fiber laminate can be stretched.

In the present invention, through the above three steps, even if wrinkles are present in the fiber laminate disposed on the core material, the surface pressure in the core material direction is applied to the sheet by the surface pressure addition step. Therefore, the wrinkles are dragged downward by the sheet and an appropriate setting force to the core material is applied.
4). Heating process Once the fiber laminate 3 has been wrinkled and stretched, even if the entire structure including the fiber laminate 3 is placed in a heating chamber as shown in FIG. good. That is, in FIG. 11, heating means 52 including a heater and a fan is provided in a heating furnace 51 having a space volume in which the entire mold 53 can be disposed. In addition, atmosphere heating such as an oven, contact heating for heating a jig or a mold, high-frequency induction heating for directly heating a fiber laminate, or the like may be employed. At this point, the fiber laminate 3 is formed into a preform without being wrinkled by the convex jig or the core material 2 described with reference to FIG.
5). Demolding process of the fiber laminate When the wrinkle stretching of the fiber laminate 3 is completed, after applying the surface pressure, the core material 2 and the preform 8a (fiber laminate) are removed from the mold 1 as shown in FIG. 3) is peeled off as a unit, or the preform 8b is peeled off from the convex jig 2 and taken out as shown in FIG.

  Although the main process of the manufacturing method of the present invention has been completed, other processes may be added as appropriate.

Next, the operation of the present invention will be described with reference to FIGS.
First, when a surface pressure indicated by an arrow is applied to the fiber laminate 3 on the convex jig 2, the wrinkles formed on the surface of the laminate are dragged down in the mold direction by the sheet back surface. At this time, since the sheet 5 has good releasability, slippage occurs on the outer peripheral surface of the laminated body 3 and the wrinkle stretching action is further promoted.

  FIG. 6 shows this state. In the figure, μ · N represents the static frictional force between the sheet 5 and the fiber laminate 3, and the downward force F applied to the sheet is larger than this value. Even if wrinkles are formed on the upper surface portion of the laminate, the wrinkles are removed. In addition, since the force F applied to the sheet 5 is smaller than σs · As shown below, the sheet 5 is not broken and the effect of allowing the preform to fit the jig 2 is exhibited. Therefore, in the manufacturing method of the present invention, the force F applied to the sheet satisfies the following formula.

μ ・ N <F <σs ・ As
Where μ: Coefficient of static friction between sheet and fiber laminate
N: Vertical effect of fiber laminate
F: Force applied to the sheet
σs: Sheet tensile strength
As: Sectional area of sheet The tensile strength σs of the sheet is calculated from the result of a test performed using the test method for the tensile properties of the film and sheet described in JIS K 7127. Moreover, as a measuring method of the static friction coefficient (mu) of a sheet | seat and a fiber laminated body, it tests using the friction coefficient test method of the film and sheet | seat described in JISK7125, and calculates from the result.

  Next, as a characteristic of the sheet 5, the following formula is satisfied in order to bring the fiber laminate into close contact with the convex jig or the core material 2. 5 and FIG. 7 which is a partially enlarged view of FIG. 5, the bending moment M of the sheet 5 has the following relationship in the present invention.

1 / ρ> -M / EI
However, ρ: curvature radius 1.0mm
M: Bending moment
E: Bending rigidity of the sheet
I: Second sectional moment of sheet Next, as a longitudinal sectional circumference of the sheet 5, as shown in the sectional view of FIG. 8, the sectional circumferential length to the contact point 11 between the sheet and the flat mold 1 is as follows. It is preferable to satisfy the formula. L2 is an example showing the sheet length within the optimum range, and L1 is a cross-sectional circumference when the sheet length is too short to cover the product line of the fiber laminate. On the other hand, L3 has a sheet length that is too long, so that the sheet comes into close contact with the convex jig or the corner portion 6 formed by the core material 2 and the mold 1 and removes wrinkles from the fiber laminate. Does not have.

L1 <L2 ≦ L3
However, L1: sheet cross-sectional circumference when it is too short
L3: Sheet cross-sectional circumference when it is too long
L2: Sheet cross-sectional peripheral length within the optimum range After all, as a preferable longitudinal cross-sectional peripheral length of the sheet 5, the sheet is bent at a position lower than the product line 12 shown in the figure, and the extension line reaches the contact 11 Is preferred. Since the length of the sheet of the present invention is such a length, the sheet is moderately exerted in the downward wrinkle effect of the wrinkles, and wrinkles on the surface of the fiber laminate are removed.

  Further, as a method other than a sheet that imparts a forcible wrinkle spreading action to the fiber laminate, the sheet 5 does not adhere to the corner portion 6 with a device that can raise and lower the convex jig or the core material 2 in the surface pressure loading step. The range may be raised or lowered. As the lifting device, an air or hydraulic cylinder, a screw-type jack bolt, or the like can be used.

  By the above actions, wrinkles on the fiber laminate are forcibly removed.

  Examples of the present invention will be described below.

Example 1
FIG. 9 is a longitudinal sectional view according to the first embodiment of the present invention, and shows a state where the planar mold 22 is sealed with the bagging film 28 and the inside is decompressed.

  First, as shown in the figure, an aluminum convex jig 23 (cross-sectional dimension: 50 mm × 80 mm, corner radius R: 5 mm) was placed on a flat mold 22. Next, adhesion of particulate resin (a component compatible with the matrix resin used in molding and glass transition temperature Tg = 68 to 72 ° C.) provided to improve the handleability such as tackiness on the convex jig 2 The fiber laminated body 24 which laminated | stacked 48 sheets (about 10 mm) of the base material (T800S, a fabric weight of 190g / m2: Toray Industries, Inc. make) was set | placed. Then, a glass cloth 26 (thickness 0.12 mm, tensile strength length 280 / width 250 N / cm, tear strength 9 N: hereinafter referred to as a sheet) coated with PTFE is disposed on the fiber laminate 24. The sheet 26 is disposed so as to cover at least the product line surface 36, and the PE tape 27 prevents the sheet from coming into close contact with the corner portion 35 formed by the convex jig 23 and the flat mold 22 even after vacuum suction. The end line was stopped.

  Next, a sealant tape 25 (SM5126: manufactured by Richmond) is pasted on the planar mold 22, a nylon tube 29 (N2-4-8 × 6: manufactured by Nitta Moore), and a bagging film 28 (HS-800: (Manufactured by Richmond) was arranged as shown in the figure and connected to the vacuum pump 30 via the nylon tube 29. Then, the space formed by the bagging film 28 and the planar mold 22 was depressurized, and it was confirmed that the degree of vacuum was 750 mmHg or more, and placed in a heating furnace. Here, the bulk density of the fiber laminate 24 was measured to be about 40%. Next, the ambient temperature was raised from room temperature of 20 ° C. to 80 ° C. at 2 ° C./min, and the fiber laminate 24 whose temperature rose with a delay was held at 80 ± 5 ° C. for 2 hours. Thereafter, the fiber laminate 24 is cooled to a temperature of 45 ° C. to eliminate the change with time of the particulate resin applied in order to improve the handling properties such as the tackiness described above, and the bulk density is measured to be about 55. %Met. Next, a template corresponding to the target bulk density was applied to the R-shaped portion 34 of the cross section. When measured with a see-through gauge, it was below the minimum measurement (0.3 mm) range, and no out-of-plane wrinkles could be measured on the R-shaped portion 34.

  The plate thickness necessary for calculating the bulk density was measured as follows. The fiber laminate 24 is sandwiched between aluminum plates having a known thickness, and the space between the aluminum plates is measured using a micrometer in a state where a surface pressure of 0.1 MPa is applied. Thereafter, the thickness of the aluminum plate was subtracted from the measured value to obtain the thickness of the fiber laminate. The number of measurements was 5 for each part, and the average value was taken. The bulk density was calculated using the following formula.

Vf = F × m / ρ / t / 10
Vf: Bulk density (%)
F: basis weight (g / m2)
m: Number of ply (sheets)
ρ: Fiber density (g / cm3)
t: Fiber laminate thickness (mm)
As a method for measuring out-of-plane wrinkles, a surface pressure of 0.1 MPa is applied to the fiber laminate, and an R-shaped template having a target bulk density is applied to the R portion of the fiber laminate in this state. Thereafter, the clearance between the template and the fiber laminate (out-of-plane wrinkles and R-shaped deviation) was measured with a see-through gauge.

Example 2
FIG. 10 shows a second embodiment of the present invention, and is a cross-sectional view when a fiber laminate is pressurized using a bag enclosing a fluid. As shown in FIG. 10, a convex jig 23 (cross section: 50 mm × 80 mm, corner R: 5 mm) was placed on a flat mold 22. Next, adhesion of particulate resin (a component compatible with the matrix resin used in molding and glass transition temperature Tg = 68 to 72 ° C.) provided to improve the handleability such as tackiness on the convex jig 23. The fiber laminate 24 in which 48 sheets (about 10 mm) of the base materials (T800S, basis weight 190 g / m ² : manufactured by Toray Industries, Inc.) were laminated was placed. Next, a glass cloth 26 (thickness 0.12 mm, tensile strength length 280 / width 250 N / cm, tear strength 9 N: hereinafter referred to as a sheet) coated with PTFE is placed on the fiber laminate 24. The PE tape is disposed so that the sheet 24 hits at least the product line surface 36, and the sheet 26 does not adhere to the corner portion 35 constituted by the convex jig 23 and the flat mold 22 even after pressing. The end line was stopped at 27.

  Next, as shown in the figure, a closed space was formed by the flat mold and the aluminum frame 33, and a silicon rubber 31 was placed in the closed space, and a fluid (pressure air) 32 was injected into the silicon rubber 31. The fluid 32 was injected into the silicon rubber 31 and expanded into a closed space, and a surface pressure was applied to the fiber laminate 24 at 110 kPa. Then, it moved in the heating furnace, heated from normal temperature (20 degreeC) to 80 degreeC at 2 degree-C / min, and the fiber laminated body 24 which temperature rose late is hold | maintained at 80 +/- 5 degreeC for 2 hours. Thereafter, the fiber laminate 24 is cooled until the temperature of the fiber laminate 24 reaches 45 ° C., thereby eliminating the change over time of the particulate resin to be imparted in order to improve the handleability such as the tackiness, and measuring the bulk density is about 55%. Met.

  Next, a template corresponding to the target bulk density was applied to the R-shaped portion of the cross section. When measured with a see-through gauge, it was below the minimum measurement (0.3 mm) range, and no out-of-plane wrinkles could be measured on the R-shaped portion 34.

  The present invention is used for stiffeners and spar preforms as molds and reinforcing members for automobiles, aircraft, ships, and industrial applications, but is not limited to this, and can be applied when making preforms having an R shape in cross section. .

In the preform manufacturing method of this invention, it is a schematic cross section which shows an example of the process of arrange | positioning a fiber laminated body on a jig or a core material. It is a schematic cross section which shows an example of the process of setting a sheet | seat further on the fiber laminated body arrange | positioned on the jig or core material used for implementation of this invention. It is a schematic cross section which shows an example of the surface pressure addition process of this invention. It is a schematic cross section which shows an example of the preform demolding process of this invention. It is a schematic cross section which shows an example of the surface pressure of a surface pressure addition process, and the state of a sheet | seat. It is the elements on larger scale which showed the force concerning the sheet | seat of the part shown with the code | symbol 10 of FIG. It is the elements on larger scale which showed the force concerning the sheet | seat of the part shown by the code | symbol 9 of FIG. It is the schematic cross section which showed the sheet length used for implementation of this invention. It is a schematic cross section which shows an example of the apparatus which enforces the manufacturing method of this invention. It is a schematic cross section which shows an example of the manufacturing apparatus of the aspect different from the apparatus of FIG. It is a schematic cross section which shows an example of the heat fixing process of this invention.

Explanation of symbols

1: Flat mold
2: Convex jig or core material
3: Fiber laminate
4: Reinforcing fiber
5: Sheet
6: Corner
7: Contact pressure
8: Preform
9: The force applied to the seat
10: Force applied to the seat
11: Contact point between planar mold and sheet
12: Product line
21: Bag figure
22: Flat mold
23: Convex jig
24: Fiber laminate
25: Sealant tape
26: PTFE coated glass cloth
27: PE tape
28: Bagging film
29: Nylon tube
30: Vacuum pump
31: Silicone rubber
32: Fluid
33: Aluminum frame
34: R-shaped part
35: Corner
36: Product line

Claims (8)

In the method of shaping a preform having a desired shape from a fiber laminate, a method for producing a preform comprising sequentially performing at least the following steps (A) to (C).
(A) A step of setting a fiber laminate in which a jig or a core material is installed on the mold surface, and a fiber laminate made of a reinforcing fiber substrate is arranged thereon.
(B) The fiber laminate is covered with a sheet, and a part of the sheet is brought into close contact with the forming die in a state where the sheet is not brought into close contact with a corner portion formed by the jig or the core material and the forming die. Sheet setting process.
(C) A surface pressure applying step of applying a surface pressure to at least a part of the sheet. The method for producing a preform according to claim 1, wherein as the fiber laminate, a particulate resin, a fibrous resin, or a film-like resin is used. The method for producing a preform according to claim 1 or 2, wherein the sheet has an elongation in the range of 0.002 to 10%. The method for producing a preform according to any one of claims 1 to 3, wherein a sheet having releasability is used as the sheet. The method for producing a preform according to any one of claims 1 to 4, wherein a surface pressure of 30 kPa to 500 kPa is applied in the surface pressure applying step. The method for producing a preform according to any one of claims 1 to 5, wherein in the surface pressure applying step, at least the following method (a) or (b) is used as a method for applying a surface pressure.
(A) A method in which the entire mold surface is covered with a bag material and the periphery is sealed, and then the closed space formed by the mold and the bag material is sucked into a reduced-pressure atmosphere.
(B) A method in which a bag containing liquid or gas is disposed on at least a part of a sheet surface placed on the mold surface together with the support structure of the bag, and the liquid or gas in the bag is pressurized and pressurized. The preform production according to any one of claims 1 to 6, wherein, in the surface pressure applying step, the entire temperature including at least the fiber laminate is heated within a range of 50C to 130C. Method. In the step of setting the fiber laminate, an apparatus for raising and lowering the jig or core material is installed on the mold, and in the surface pressure applying process, the jig or core material is a mold and the jig or core material. The method for manufacturing a preform according to any one of claims 1 to 7, wherein the operation is performed so that the sheet can be lifted and lowered within a range in which the sheet does not adhere to the corner portion.

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