JP2002172630A - Vacuum-molding method for frp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the fiber volume content of an FRP by increasing a pressurizing force by a bag member, and improve the quality and the physical property of the FRP by increasing the sealing performance of the bag member, and shorten the molding cycle in a vacuum molding of the FRP using the bag member. SOLUTION: At least a reinforcing fiber base material is arranged in the cavity of a die. Then, the bag material is arranged on the surface side of the die, and thus, the inside of the cavity is bagged and sealed. Then, the inside of the cavity is vacuumized, and at the same time, a resin is injected into the cavity for this vacuum molding method of the FRP. In such a vacuum molding method for the FRP, the bagging is doubly performed by using two sheets of the bag materials, and a space between both bag materials is vacuumized as well for the vacuum molding method for the FRP. Also, the sealing is doubly performed by the sealing material of the bag material, and a space between both sealing materials is vacuumized as well for the vacuum molding method for the FRP.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for vacuum forming an FRP, and more particularly to a method for vacuum forming an FRP by bagging and sealing a surface of a single-sided mold.

[0002]

2. Description of the Related Art Heretofore, at least a reinforcing fiber base material has been arranged in a single-sided mold cavity, a bag material has been arranged on the surface side of the mold, and the inside of the cavity has been bagged and sealed. There is known a so-called FRP vacuum molding method in which a resin is injected into a resin. In this method, as the bag material, for example, 1
A sheet material made of a film or a rubber material is used, and an adhesive rubber sealing material, for example, is interposed between the periphery of the bag material and the mold surface in order to seal the inside of the cavity.

[0003]

However, the conventional FRP vacuum forming method as described above has the following problems. First, one of the advantages of vacuum molding as described above is that the bag material made of sheet material naturally follows the shape of the surface of the internal filling base material due to the reduced pressure in the cavity, and the resin can be injected in that state, The object is to easily form the surface shape of an object into a desired shape. However, the resin is injected at atmospheric pressure or low pressure, but due to the pressure applied by the resin injection, the resin injected into the cavity tends to swell together with the reinforcing fiber base due to the static pressure of the resin. The pressure difference between the pressure applied by the material and the static pressure of the resin becomes small, and it is difficult to completely suppress the pressure from the outside with the pressure before the resin injection. Therefore, there is a problem that it is difficult to increase the volume content of the reinforcing fibers in the molded product to a certain level or more. When the volume content of the reinforcing fibers is low, the mechanical properties of the FRP decrease accordingly.

[0004] In addition, the reduced pressure state in the cavity (that is,
The better the vacuum suction condition is, the more quickly and uniformly the resin can be impregnated into the reinforcing fiber base material. For that purpose, the bag material needs to be securely sealed at the periphery. . If the seal is incomplete, air leakage or the like into the cavity will occur, causing voids or the like to occur in the molded product. In addition, the time required to reach a predetermined degree of pressure reduction becomes longer, the molding cycle becomes longer, and as a result, molding costs increase. As described above, the sealing portion in the conventional molding method is merely provided with the rubber sealing material having adhesiveness, and there is a possibility that a poor sealing due to insufficient adhesion to the bag material may occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of vacuum forming an FRP in which a bag is used to cover a filling material in a cavity of a mold with bagging and sealing, without impairing the function as a bag material. An object of the present invention is to provide a molding method capable of increasing a pressing force and thereby improving a fiber volume content of FRP molded.

Another object of the present invention is to improve the sealing performance in the cavity by the bag material, thereby improving the quality of the molded FRP (suppressing the generation of voids, etc.) and improving the molding cycle. It is an object of the present invention to provide an FRP vacuum forming method capable of reducing the time required for forming and reducing the forming cost.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, a method for vacuum forming an FRP according to the present invention comprises disposing at least a reinforcing fiber base material in a cavity of a mold, and placing a bag material on the surface side of the mold. In the vacuum molding method of the FRP in which the cavity is bagged and sealed, and the inside of the cavity is decompressed and the resin is injected into the cavity, the bagging is performed by double bagging using two bag materials. The method is characterized in that the pressure between the bag materials is also reduced.

In this vacuum forming method, it is preferable to interpose a spacer between both bag materials. As a spacer, a porous sheet base material having a predetermined thickness,
Powders, granules and the like can be used. Further, it is preferable that both the bag materials are independently sealed to the mold.

Further, in the method of vacuum forming an FRP according to the present invention, at least a reinforcing fiber base material is arranged in a cavity of a mold, a bag material is arranged on a surface side of the mold, and the inside of the cavity is bagged and sealed. In the vacuum forming method of FRP in which the inside is depressurized and the resin is injected into the cavity, as the bagging, a sealing material is double-laid between the periphery of the bag material and the mold, and the pressure is also reduced between the two sealing materials. And a method characterized by the following.

It is preferable to use an elastic sealing material such as an O-ring as the sealing material. Also,
As a bag material, for example, a stretchable rubber sheet,
A rigid plate-shaped bag material whose peripheral edge, that is, a portion in contact with the sealing material, has elasticity (for example, at least the peripheral edge is formed of a rubber sheet) can be used.

At least a reinforcing fiber base is disposed in the cavity of the mold. When a core material is disposed together therewith, the effect of the method according to the present invention is large. That is, since the basic shape of the FRP to be molded is determined by the presence of the core material, the reinforcing fiber base material disposed on the core material and the bag material covering the reinforcing fiber base material can easily follow the predetermined shape. it can.

In the above-described method of vacuum forming an FRP according to the present invention, double bagging is performed using two bag materials, and the pressure between the two bag materials is reduced (particularly, a spacer is provided between the two bag materials). During the depressurization in the cavity, both the bag materials are deformed in the cavity direction so as to follow the surface shape of the filling in the cavity, and the two bag materials are separated by a predetermined distance. While maintaining and being deformed into the above-mentioned predetermined shape as a whole, a pressure is applied in the direction of the cavity as if it were a single rigid plate by the atmospheric pressure acting from the outside. Therefore, when the resin is injected into the cavity and the reinforcing fiber base is swelled together with the resin by the pressing force acting from the inside due to the static pressure of the resin accompanying the injection,
Since there is no resin that causes a reaction force on the inner side of the second bag material, a pressing force acts from the outside toward the cavity with a sufficient pressing force due to the atmospheric pressure, suppressing the inflation pressure from the inside of the cavity, It is possible to hold the inner filling with a sufficiently large pressing force. As a result, the volume content of the reinforcing fibers can be sufficiently increased,
The physical properties of the molded FRP can be improved.

Further, the peripheral portion of the bag material is sealed with a double-layered sealing material, and the pressure between the two sealing materials is reduced, so that the peripheral portion of the bag material is sucked at this portion and the two sealing materials are satisfactorily applied. In close contact. In particular, in the case of the inner seal material, both the reduced pressure suction force between the two seal materials and the suction force by depressurizing the inside of the cavity act, so the inner seal material and the bag material are particularly It adheres strongly and so-called self-sealing is performed very well. As a result, the sealing performance at the peripheral portion of the bag material is greatly improved, problems such as generation of voids in the molded FRP due to air leakage from the outside are eliminated, and the quality of the FRP is improved, and the inside of the cavity is maintained at a predetermined level. The time for reducing the pressure is reduced, and the molding cycle of the FRP is shortened.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of an FRP vacuum forming method according to one embodiment of the present invention. In FIG. 1, in a cavity 2 of a one-sided mold 1, a core material 3 made of a lightweight material such as a foam material and formed into a predetermined shape, and a reinforcing fiber base material 4 disposed on the outer surface of the core material 3 And are accommodated. On the front side of the mold 1, bag members 5a and 5b made of two flexible sheet materials are provided,
The inside of the cavity 2 is double bagged. Bag material 5
a and 5b are seal members 6 whose peripheral portions are each independently.
The space between the mold 1 and the surface is sealed by a and 6b.

In this embodiment, a spacer 7 is interposed between the two bag members 5a and 5b. As the spacer 7,
It is possible to use a porous sheet material or net material, or a powder or granules capable of maintaining a predetermined interval between the two bag materials 5a and 5b. The pressure between the two bag members 5a and 5b can be reduced by air suction through the suction port 8.

In the cavity 2 of the mold 1, the core material 3 and the reinforcing fiber base 4 are arranged, and after performing the above-mentioned double bagging,
The pressure is reduced to a predetermined pressure reduction degree (vacuum degree) by the air suction through the suction port 9. Substantially at the same time as or after this decompression, the resin 11 stored in the resin tank 10 is
Is injected into the cavity 2 through the injection port 12.
This injection is basically performed by utilizing the fact that the resin 11 naturally flows into the cavity 2 due to the difference between the atmospheric pressure applied to the stored resin surface of the resin tank 10 and the reduced pressure in the cavity 2. Although good, a slight resin injection pressure may be applied as needed.

The operation of the above-described FRP vacuum forming method will be described with reference to FIG. FIG. 2 shows FIG.
FIG. 3 shows, in principle, bagging and sealing states during molding by resin injection in the FRP vacuum molding method as shown in FIG. The pressure between the two bag members 5a and 5b is reduced to, for example, Va ′ by air suction, and the pressure in the cavity 2 of the mold 1 is also reduced to, for example, Va by vacuum. Va ′ and Va may be the same value or different values. Due to both pressure reductions, the bag materials 5a and 5b in which the spacer 7 is interposed between the reinforcing fiber bases are
a, 5b while maintaining a predetermined interval
In the present embodiment, it is deformed toward the cavity 2 so as to conform to the surface shape of the inner filling material, and in this embodiment, to conform to the surface shape of the outer reinforcing fiber base material 4.

In this state, the resin 11 is injected into the cavity 2. With this injection, the resin 11 flowing into the cavity 2 applies resin pressure to the cavity 2. Due to this resin pressure, the filling in the cavity 2,
In particular, the reinforcing fiber base 4 tends to expand outward. However, since the bag material 5a, 5b of the double bagging is sealed at a desired degree of pressure reduction by being sealed between the two by the sealing materials 6a, 6b, it behaves as if it were a single rigid plate. Due to the pressure difference between the atmospheric pressure applied from the side and the reduced pressure in the cavity 2, a sufficiently high pressure is applied in the cavity 2 direction. This pressing force is applied to both bag materials 5a,
5b is exhibited in a state along the surface shape of the filling material in the cavity 2. Therefore, cavity 2
When the inflation pressure is applied from the inside to the outside of the cavity 2 due to the injection of the resin into the inside, when the reinforcing fiber base 4 tries to expand outward, the resin and the reinforcing fiber base are held in a predetermined shape. The pressed bag members 5a and 5b press down with sufficiently high external pressure. As a result, the fiber volume content of the molded FRP is greatly increased, and the physical properties of the FRP are improved.

FIG. 3 shows an FR according to another embodiment of the present invention.
3 shows the state of implementation of a vacuum forming method for P. In FIG. 3, a core material 23 and a reinforcing fiber base 24 are arranged in a cavity 22 of a mold 21, and they are bagged and sealed by a bag material 25 arranged on the surface side of the mold 21. Air is sucked from the cavity 22 through the suction port 26, and the pressure in the cavity 22 is reduced to a predetermined pressure.
In this state, resin is injected as in the above-described embodiment.

A groove 27 for a sealing material extending annularly is provided on a portion of the front surface of the mold 21 which faces the peripheral portion of the bag material 25.
a and 27b are provided inside and outside in a double manner, and sealing materials 28a and 28b are respectively provided in the grooves 27a and 27b.
Is installed. The sealing members 28a, 28b are made of, for example, O-rings having elasticity, and the respective grooves 27a, 27
It is mounted in a state protruding from b by, for example, about 2 to 4 mm.

A mold 2 is provided between the two sealing members 28a and 28b.
Air is sucked in through the suction port 29 provided in 1, and the pressure between the sealing materials 28 a and 28 b is reduced, so that the peripheral edge of the bag material 25 is strongly adhered to the sealing materials 28 a and 28 b. Further, the bag material 25
Is particularly in close contact with the inner seal member 28b.
That is, each of the sealing materials 28a, 28
b is self-sealed. The degree of reduced pressure Va ″ between the two seal materials 28a and 28b and the degree of reduced pressure Va between the cavities 22 may be the same value or different values.

In the present embodiment, the bag material 25 is made of a highly elastic and stretchable, for example, rubber bag material at the center thereof, and its peripheral portion is made of the same material but has relatively low elasticity. It is formed in a thick part.

In the FRP vacuum forming method according to the present embodiment, the seals 28a and 28b are double-sealed and the seals 28a and 28b are both sealed.
Since the pressure between the spaces b is reduced, the two sealing members 28a and 28b are satisfactorily self-sealed, so that the periphery of the bag member 25 can reliably seal the inside of the cavity 22 with a much higher sealing force than the conventional sealing method. Become like As a result, air leakage from the outside into the cavity 22 and the like are reliably avoided, problems such as generation of voids in the molded FRP are solved, and quality and physical properties of the FRP are improved. In addition, as a result of the improvement in the sealing performance, the time required for reducing the pressure inside the cavity 22 to a predetermined degree is reduced, so that the molding cycle for continuously producing the FR product is significantly reduced. .

The form of the bag material is not limited to that shown in FIG. 3, and for example, as shown in a modified example in FIG. 4, the central portion of the bag material 31 is formed of a rigid plate 32 having a predetermined shape, The portion may be formed of a sheet material 33 having elasticity, for example, a rubber sheet. According to this structure, the sheet material 33 having elasticity is used as the sealing material 2.
8a, 28b, the sealing material 28 is better
a, 28b. In particular, the inner seal member 28b can be better self-sealed through both the reduced pressure between the seal members 28a and 28b and the reduced pressure in the cavity 22, and the peripheral portion of the bag member 31 is reliably sealed. As a result, the quality and physical properties of the molded FRP are improved, and the molding cycle is shortened.

The reinforcing fiber substrate applied in the method according to the present invention is not particularly limited, and any type of reinforcing fiber can be used, and the form thereof may be any form such as a woven fabric, a unidirectionally drawn fiber, or a mat. It can be adopted, and the laminated structure is not limited at all. Further, the present invention can be applied to a case where only a reinforcing fiber base is disposed in a cavity without providing a core material.

[0026]

As described above, the FR according to the present invention is used.
According to the vacuum forming method of P, by applying double bagging during bagging and reducing the pressure between both bag materials, the pressure applied by the bag material to the filling in the cavity can be increased, and the fiber of the FRP to be formed By increasing the volume content, the physical properties of FRP can be improved.

Also, by double sealing the peripheral portion of the bag material and reducing the pressure between the two seal materials, the sealing performance with respect to the inside of the cavity can be greatly improved, and air leakage from the outside can be reliably prevented. The quality and physical properties of the molded FRP can be improved, and the time required to reduce the pressure inside the cavity to a predetermined degree of pressure can be shortened to shorten the molding cycle and reduce the molding cost.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an apparatus for performing a vacuum forming method of an FRP according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram for explaining an operation at the time of resin injection of a vacuum molding method using the apparatus of FIG.

FIG. 3 is a partial schematic configuration diagram of an apparatus for performing an FRP vacuum forming method according to another embodiment of the present invention.

FIG. 4 is a partial schematic configuration diagram of an apparatus according to a modification of FIG.

[Explanation of symbols]

 1, 21 mold 2, 22 cavity 3, 23 core material 4, 24 reinforcing fiber base material 5a, 5b, 25, 31 bag material 6a, 6b, 28a, 28b sealing material 7 spacer 8, 9, 26, 29 suction port 10 Resin tank 11 Resin 27a, 27b Groove for sealing material 32 Rigid plate 33 Elastic sheet material

Claims (7)

[Claims] At least a reinforcing fiber base material is arranged in a cavity of a mold, a bag material is arranged on the surface side of the mold, bagging and sealing are performed in the cavity, and the inside of the cavity is depressurized and resin is injected into the cavity. A vacuum forming method for an FRP, wherein the bagging is performed by double bagging using two bag materials, and the pressure between both bag materials is reduced. 2. A spacer is interposed between both bag materials.
A method for vacuum forming an FRP according to claim 1. 3. The method for vacuum forming an FRP according to claim 1, wherein both the bag materials are independently sealed to a mold. 4. At least a reinforcing fiber base is arranged in a cavity of a mold, a bag material is arranged on the surface side of the mold, bagging and sealing is performed in the cavity, and pressure is reduced in the cavity and resin is injected into the cavity. A vacuum forming method for an FRP, wherein the bagging is performed by arranging a double sealing material between the peripheral portion of the bag material and the mold, and reducing the pressure between both the sealing materials. . 5. The method of claim 4, wherein a resilient sealing material is used. 6. The FR according to claim 4, wherein a bag material having elasticity at least in contact with the seal material is used.
P vacuum forming method. 7. The FR according to claim 1, wherein a core material is disposed in the cavity together with the reinforcing fiber base material.
P vacuum forming method.