JPH05162191A - Production of frp blow molded product - Google Patents

Abstract

PURPOSE:To easily produce a product having superior characteristics by a method wherein fiber substrates are molded into a piece when a thermosetting resin infiltrated thereto is half cured, a hollow body is formed by blowing air into a parison inserted into the fiber substrate molded piece, and thereafter the thermosetting resin is completely cured. CONSTITUTION:In the production of an FRP blow molded product 10, firstly fiber substrates 40, 41 are set to inner molds 25, 31 of a split mold for split molding a fiber substrate molded piece 43; the inner molds 25, 31 are closed with outer molds; a thermosetting resin is injected into each cavity of the split mold to be infiltrated into the fiber substrates 40, 41; and the thermosetting resin is half cured by adjusting a temperature of the split mold. Succeedingly, the respective fiber substrates 40, 41 are taken off to be set to a parison mold made of the inner molds 25, 31 to be molded into the fiber substrate molded piece 43. Air is blown into a parison 45 inserted into the molded piece 43 to bring a hollow body 46 into close contact with the inner surface of the molded piece 43. After that, the thermosetting resin is completely cured by adjusting the temperature of the parison mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an FRP hollow molded article, and more particularly to a method for producing an FRP hollow molded article containing a hollow body made of a thermoplastic resin.

[0002]

2. Description of the Related Art As a method for producing an FRP (fiber reinforced resin) molded product, for example, a resin hollow molded product, various methods have been conventionally proposed. These methods can be roughly classified into the following five types. Adhesion Method Blow Molding Method Gas Injection Molding Method (Blow Molding Method + Hand Lay-Up) Molding Method Wind-Ben Core Molding Method Hereinafter, the above methods will be briefly described.

In the bonding method (1), two-divided hollow molded bodies 1, 1 which are separately molded in advance as shown in FIG. 15 (a), are bonded at the bonding surfaces 2 and 2 shown by diagonal lines, and shown in FIG. 15 (b). This is a method for producing the hollow molded body 3.

In the blow molding method of FIG.
As shown in (a), the parison 8 of thermoplastic resin, which is discharged from the die 7 and closed at one end, is inserted into the cavity 6 formed by the molding dies 4 and 5, and then the die 7 is moved as shown in FIG. 16 (b). Air 9 is blown into the parison 8 to inflate the parison 8 so that the parison 8 contacts the mold surfaces of the molds 4 and 5, and then the parison 8 is cooled and solidified. Next, as shown in FIG. 16C, the molding dies 4 and 5 are opened to take out the hollow molded body 10 (Japanese Patent Publication No. 57-14969).
Japanese Patent Application Laid-Open No. 2-99319 and Japanese Patent Application Laid-Open No. 3-7
3316 gazette).

The gas injection molding method (1) is a hollowing method in the injection molding of a thermoplastic resin. As shown in FIG. 17 (a), the thermoplastic resin 12 is injected into the cavity of the molding die 11 so that the molding surface of the molding die 11 can be molded. After the thermoplastic resin 12 in the vicinity is cooled and solidified, air is injected as shown in FIG.
This is a method of hollowing out by eliminating 2 and forming a space 13 (see Japanese Patent Publication No. 57-14968).

[Blow molding method + hand layup]
In the molding method, the blow-molded body 14 is molded in advance as shown in FIG. 18 (a), and then the FRP layer 15 is formed on the surface of the blow-molded body 14 by hand lay-up as shown in FIG. 18 (b). 57-14970).

[0007] The method for molding a wind-blade core is a method for molding an FRP hollow body, and as shown in Fig. 19 (a), the reinforcing fiber base material 1 is formed so as to cover the surface of the wind-blade 16 formed of a predetermined material.
7 is set, and as shown in FIG.
After being set in the cavity, the liquid reactive resin 19 is injected to impregnate the reinforcing fiber base material 17. At this time, the internal pressure is applied to the normal windshield 16 by the air 9. Next, the liquid reactive resin 19 is cured to obtain an FRP hollow body.

[0008]

However, the above-mentioned or prior art methods have various problems. That is,
In the bonding method (1), it is necessary to mold the divided molded body in advance, and further a bonding step for the divided molded body is required. In the blow molding method and the gas injection molding method of, the above problems are solved, and both methods are usually applied to the resin alone or the short fiber reinforced resin system,
Therefore, it is difficult to apply to high strength and high rigidity molded products.

[Blow molding method + hand layup]
High strength and high rigidity molded products can be obtained by using the molding method and the air core molding method. However, the hollow molded article obtained by the method (1) has a problem that interface peeling between the FRP layer on the surface and the blow molded article inside tends to occur at high load. Moreover, F obtained by using the method of
Since the RP hollow body uses a wind fan as a core, when the wind fan is left inside the final product, the FRP hollow body, the heat resistance of the wind fan becomes a problem. When taken out from the body, there is a problem with the hermeticity of the FRP hollow body.

The present invention is intended to solve the above-mentioned problems of the prior art, and an object of the present invention is to easily form an FRP hollow molded article having high strength, high rigidity, high heat resistance and hermeticity. It is to provide a method that can be obtained.

[0011]

Means for Solving the Problems The method for producing an FRP hollow molded article of the present invention comprises (1) a split mold for splitting each part of a fiber base molded article, which comprises a pair of an outer mold and an inner mold. The step of setting the fiber base material on each inner mold surface, (2) the step of clamping the inner mold set with the fiber base material and the respective outer dies forming a pair, and (3) the mold clamping The step of injecting a thermosetting resin into the cavity of each split mold to impregnate each fiber base material, and (4) adjusting the die temperature of each split mold to thermoset the fiber base material (5) Taking out each fiber base material in which the thermosetting resin impregnated in the semi-cured state is taken out and set so that the whole is integrated with the mold surface of the parison mold. And forming a fiber base material molded body, and (6) made of a thermoplastic resin in the fiber base material molded body and closed at one end Inserting a parison,
(7) A step of blowing air into the parison to form a hollow body made of a thermoplastic resin in close contact with the inner wall surface of the fiber base material molding, and (8) adjusting the mold temperature of the parison molding die to form the fiber base material. And a step of completely curing the impregnated thermosetting resin.

The split mold used in the step (1) is for molding individual parts obtained by splitting a predetermined number of fibrous base molded articles constituting the desired FRP hollow molded article.
The size, shape, number of divisions, etc. of the split mold are appropriately selected according to the size and shape of the FRP hollow molded body. The fibrous base material may be the one conventionally used as a reinforcing material in this field, such as glass fiber of various properties. One kind of fiber base material may be set, or two or more kinds may be set in combination.

In step (2), the outer mold and the inner mold are clamped to mold the divided individual parts of the fiber base material molded body.

The thermosetting resin used in the step (3) may be a conventional one such as an unsaturated polyester resin or a phenol resin, either alone or in combination. The injection amount of the thermosetting resin is determined so that the desired performance can be obtained.

In step (4), the mold temperature of each split mold is appropriately adjusted to bring the thermosetting resin impregnated into each fiber base material into a semi-cured state. The mold temperature at this time is adjusted according to a predetermined pattern so that an appropriate semi-cured state can be obtained according to the properties of the thermosetting resin. The mold temperatures of the split molds are not necessarily the same.

The size and shape of the entire fiber base material are formed by integrating the fiber base materials in the step (5).
Further, the parison molding die used is a molding die for molding the final shape of the desired FRP hollow molded article, and at the same time is a molding die for molding the parison. The parison molding die may be a separate body from the split molding die, but may be formed by combining the inner mold of the split molding die, for example.

In step (6), a parison of a predetermined size, which is made of a thermoplastic resin and is closed at one end, is inserted from the die of the blow molding machine into the fiber base molding.

In step (7), the hollow body is brought into close contact with the inner wall surface of the inside of the molded fiber base material and blow molded. At this time, the outer surface of the blow molded hollow body and the inner wall surface of the fiber base molded body are firmly fixed.

When the thermosetting resin is completely cured in step (8), the desired FRP hollow molded article can be obtained. The mold temperature of the parison mold at this time is optimally selected so as to completely cure the thermosetting resin and not melt the thermoplastic resin.

[0020]

In the method of the present invention, the fibrous base materials in which the impregnated thermosetting resin is in a semi-cured state are integrally bonded to form a fibrous base material molded body. The blow-molded hollow body is firmly fixed to the fiber-based molded body by the anchor effect and has a good hermeticity.

[0021]

The present invention will be described in more detail by the following examples.

FIG. 1 shows the FR obtained by the method of the present invention.
The fractured state of an example of the P hollow molded body 20 is shown. Further, FIG. 2 is an enlarged view of a portion A of the FRP hollow molded body 20 of FIG. The FRP hollow molded body 20 includes a hollow body layer 21 made of a thermoplastic resin, a coarse fiber base material 22 impregnated with a thermosetting resin, and a fine fiber base material 23 impregnated with a thermosetting resin.

FIG. 3 shows a split molding die for split-molding each part of the fiber base material molded body. FIG. 3A is a split mold for molding the left half of the fiber base molded body, and FIG. 3B is a split mold for molding the right half of the fiber base molded body.
Further, each inner mold of these split molds is also used for molding the FRP hollow molded body 20.

In the split mold of FIG. 3A, the outer mold 24 and the inner mold 25 form a cavity 26,
6 is sealed by an O-ring 28 in the groove 27. Further, a predetermined amount of thermosetting resin is injected through the injection hole 29. Similarly,
The split mold of FIG. 3B has an outer mold 30, an inner mold 31, a cavity 32, a groove 33, an O-ring 34, and an injection hole 35.

FIG. 4 shows the split mold of FIG. 3 (a) opened, FIG. 4 (a) shows the inner mold 25, and FIG. 4 (b) shows the outer mold 24. The inner mold 25 and the outer mold 24 respectively include a pipe 36 (arranged around the cavity 26) and a pipe 37 (cavity 32) through which a heat medium necessary for adjusting the mold temperature, for example, heat transfer oil, hot water, steam or the like is passed. Are arranged around). Similarly, FIG. 5 shows a state in which the split mold of FIG. 3 (b) is opened, and FIG. 5 (a) shows the inner mold 31.
5 (b) shows the outer mold 30. Inner mold 31 and outer mold 3
0 also has a pipe 38 and a pipe 39, respectively.

Hereinafter, the method of the present invention will be described in detail with reference to FIGS.

FIG. 6 shows step (1) of the method of the present invention. As shown in FIG. 6A, the fiber base material 40 is formed on the mold surface of the inner mold 25.
[Continuous Strand Mat (Meshsuke 200-40
0 g / m ² , diameter 10-20 μm), chopped strand mat (area weight 200-400 g / m ² , diameter 10-
20 μm), roving cloth (Basis weight 300-600 g
/ M ² , diameter 10-20 μm)] and a fiber base material 41 [Continuous Strand Mat (Basis weight 400-600 g)
/ M ^2, diameter 10-20), chopped strand mat (weight per unit area 400-600 g / m ^2, diameter 10-20
μm), glass cloth (basis weight 200-500 g / m ² ,
Diameter 10-20 μm)] is sequentially laminated to set a fiber base material for forming the left half of the fiber base material molded body. It should be noted that a relatively fine mesh fiber base material was used as the fiber base material 40, and a relatively coarse mesh fiber base material was used as the fiber base material 41. Similarly, as shown in FIG. 6B, a fiber base material for forming the right half of the fiber base material molded body is formed by sequentially laminating the fiber base material 40 and the fiber base material 41 on the mold surface of the inner mold 31. set. In addition, when high quality is required for the surface, before laminating the fiber base material 40, the surface mat (area weight 20-80 g / m ² , diameter 10
-20 μm) is preferably laminated.

FIG. 7 shows step (2) of the method of the present invention. As shown in FIG. 7A, the inner mold 25 and the outer mold 24 are clamped to mold the left half of the fiber base material molded body. Similarly, FIG.
As shown in (b), the inner mold 31 and the outer mold 30 are clamped to mold the right half of the fiber base material molded body.

FIG. 8 shows step (3) of the method of the present invention. As shown in FIG. 8A, the thermosetting resin is injected into the cavity 26 from the injection hole 29 to form the fiber base material 40 and the fiber base material 4.
The thermosetting resin is impregnated in the left half of the fibrous base material molded body by impregnating No. 1 with the thermosetting resin. Similarly, as shown in FIG. 8B, the thermosetting resin is injected into the cavity 32 through the injection hole 35 to impregnate the right half of the fiber base molded body with the thermosetting resin. The thermosetting resin may be any resin generally used for FRP liquid molding, and examples thereof include epoxy resin, unsaturated polyester resin, phenol resin, vinyl ester resin and the like.

FIG. 9 shows step (4) of the method of the present invention. As shown in FIG. 9 (a), oil (mineral oil, synthetic oil, etc.), hot water (steam), etc., is passed through the pipe 36 and the pipe 37 as a heat medium to adjust the mold temperature to a predetermined temperature for a predetermined time, and to The thermosetting resin impregnated in the base material 40 and the fiber base material 41 is brought into a semi-cured state. Similarly, as shown in FIG. 9B, the fiber base material 40 and the fiber base material 41 are impregnated by passing oil (mineral oil, synthetic oil, etc.), hot water (steam) or the like through the pipe 38 and the pipe 39. The thermosetting resin is semi-cured. A cartridge heater may be embedded and used instead of the pipe.

FIG. 10 shows step (5) of the method of the present invention.
Take out each fibrous base material in which the impregnated thermosetting resin is in a semi-cured state, and then combine the inner mold 25 and the inner mold 31 so that the whole is integrated with the mold surface of the parison molding mold. The fiber base molded body 43 is formed by setting.

FIG. 11 shows step (6) of the method of the present invention.
A parison 45 of a predetermined size, which is made of a thermoplastic resin discharged from a die 44 and has one end closed, is inserted into the fiber base material molded body 43. The thermoplastic resin only needs to be blow-moldable, such as HDPS (high density polyethylene), P
Examples include PS and PP.

FIG. 12 shows step (7) of the method of the present invention.
Air 9 is blown into the parison 45 from the die 44 to form a hollow body 46 made of a thermoplastic resin in close contact with the inner wall surface of the fibrous base material molded body 43. At this time, the fiber base material molded body 43
Since the inner wall surface is made of the coarse fiber base material 41, the hollow body 4
An anchor effect occurs between 6 and the coarse fiber base material 41, and the hollow body 46 and the fiber base material molded body 43 are firmly bonded to each other.

FIG. 13 shows step (8) of the method of the present invention.
By passing oil (mineral oil, synthetic oil, etc.), hot water (steam) or the like as a heat medium through the pipes 36 and 39, the mold temperature of the parison mold is adjusted to a predetermined temperature for a predetermined time, and a fiber base material molded body is obtained. The thermosetting resin impregnated in 43 is completely cured.

After the thermosetting resin is completely cured, it is cooled and then released from the parison mold to obtain the FRP hollow molded body 20 shown in FIG.

[0036]

As described above, the method for producing an FRP hollow molded article of the present invention comprises a step of setting a fiber base material on each inner die surface of the split molding die, and a step of forming each inner die and each outer die. Tightening step, step of injecting thermosetting resin into the cavity of each split mold to impregnate each fiber base material, and adjusting mold temperature of each split mold to semi-harden thermoset resin And a step of taking out each fiber base material in which the thermosetting resin is in a semi-cured state and setting it on the mold surface of the parison molding die to form a fiber base material molded body, The process of inserting a parison made of thermoplastic resin, the process of blowing air into the parison to form the hollow body in close contact with the inner wall surface of the fiber base molded body, and the thermosetting by adjusting the mold temperature of the parison mold. It consists of the step of completely curing the resin, so that the impregnated thermosetting Since each fiber base material in which the resin is in a semi-cured state is integrally bonded to form a fiber base material molded body, and the joint portion of each fiber base material is firmly bonded in the subsequent curing process, conventional adhesion There is no need to provide a separate bonding step as in the method. Further, unlike the conventional (blow molding method + hand layup) molding method, there is no need for hand layup, and the productivity is excellent.

In addition, the hollow body blow-molded in the fiber base molded body is firmly adhered to the surface of the fiber base molded body in a semi-cured state while it is still soft by the anchor effect, so that there is a risk of delamination. Instead of the conventional (blow molding method +
It is possible to easily obtain an FRP hollow molded article having excellent mechanical strength, heat resistance and durability as compared with the hand lay-up) molding method.

Further, since the entire hollow body is integrally molded, there are no cracks and the like, and the heat resistance and sealing property of the FRP hollow molded body obtained are higher than those obtained by the conventional wind-sheath core molding method.

Furthermore, when the parison is inflated to form a hollow body, the fiber base material layer in the semi-cured state is also subjected to pressure, so that the fiber density of the fiber base material layer is increased and the obtained FR is obtained.
The mechanical strength and rigidity (elastic modulus) of the P hollow molded article are improved.

[Brief description of drawings]

FIG. 1 is a cutaway perspective view of an example of an FRP hollow molded article obtained by the method of the present invention.

FIG. 2 is an enlarged view of a portion A of the FRP hollow molded body of FIG.

FIG. 3 is a cross-sectional view of an example of a split molding die used for split-molding each part of the fiber-based molded article in the method of the present invention.

FIG. 4 is a perspective view showing a state where the split mold of FIG. 3 (a) is opened.

5 is a perspective view showing a state in which the split mold of FIG. 3 (b) is opened.

FIG. 6 is an explanatory diagram of a step (1) of an example of the method of the present invention.

FIG. 7 is an explanatory diagram of a step (2) of an example of the method of the present invention.

FIG. 8 is an explanatory diagram of step (3) of an example of the method of the present invention.

FIG. 9 is an explanatory diagram of step (4) of an example of the method of the present invention.

FIG. 10 is an explanatory diagram of step (5) of an example of the method of the present invention.

FIG. 11 is an explanatory diagram of step (6) of an example of the method of the present invention.

FIG. 12 is an explanatory diagram of step (7) of an example of the method of the present invention.

FIG. 13 is an explanatory diagram of step (8) of an example of the method of the present invention.

FIG. 14 is a cross-sectional view of an example of an FRP hollow molded body obtained by the method of the present invention.

FIG. 15 is an explanatory diagram of an example of a conventional bonding method.

FIG. 16 is an explanatory diagram of an example of a conventional blow molding method.

FIG. 17 is an explanatory diagram of an example of a conventional gas injection molding method.

FIG. 18 Conventional (blow molding method + hand layup)
It is explanatory drawing of an example of a molding method.

FIG. 19 is an explanatory diagram of an example of a conventional wind-sheath core forming method.

[Explanation of symbols]

 1 Two-division hollow molded body 2 Adhesive surface 3,10 Hollow molded body 4,5,11,18 Mold 6,26,32 Cavity 7,44 Die 8,45 Parison 9 Air 12 Thermoplastic resin 13 Space 14 Blow molded product 15 FRP layer 16 Windshield 17 Reinforcing fiber base material 19 Liquid reactive resin 20 FRP hollow molded body 21 Hollow body layer 22 Coarse fiber base material layer 23 Fine fiber base material layer 24, 30 Outer mold 25, 31 Mold 27,33 Groove 28,34 O-ring 29,35 Injection hole 36,37,38,39 Piping 40,41 Fiber base material 42 Thermosetting resin 43 Fiber base material molded body 46 Hollow body

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Claims (1)

[Claims] (1) A step of setting a fiber base material on each inner mold surface of a split molding die which is a pair of an outer mold and an inner mold for separately molding each portion of the fiber base material molded body, (2) A step of clamping each inner mold set with the fiber base material and each outer mold paired with the inner mold, and (3) injecting a thermosetting resin into the cavity of each divided mold which has been clamped. Impregnating each fiber substrate, (4) adjusting the mold temperature of each split mold to make the thermosetting resin impregnated in each fiber substrate into a semi-cured state, and (5) impregnating And a step of taking out each fiber base material in which the thermosetting resin is in a semi-cured state and setting it so that the whole is integrated with the mold surface of the parison forming mold to form a fiber base material molded body, (6) A step of inserting a parison, which is made of a thermoplastic resin and has one end closed, into the fiber base molded body;
(7) A step of blowing air into the parison to form a hollow body made of a thermoplastic resin in close contact with the inner wall surface of the fiber base material molding, and (8) adjusting the mold temperature of the parison molding die to form the fiber base material. And a step of completely curing the impregnated thermosetting resin.