JP2582335B2 - Method and apparatus for molding fiber-reinforced plastic moldings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for molding a fiber-reinforced plastic molded product suitable for, for example, high-mix low-volume production.

[0002]

2. Description of the Related Art Conventionally, as a method for molding a fiber-reinforced plastic molded article of this type, for example, as described in Japanese Patent Application Laid-Open No. 1-113441, a fiber-reinforced material is impregnated with an unsaturated polyester resin composition containing a curing catalyst and the like. It is known that after foaming, the fiber reinforced material is integrated into a sheet shape between films to form a sheet material, and the sheet material is vacuum formed and cured.

[0003]

However, in the case of the above-mentioned conventional structure, the use of a vacuum generator has a disadvantage in terms of economical efficiency due to the high equipment cost of the whole apparatus. Heating for curing has a structure that depends only on the heat from the heating mold.Therefore, since the heat curing time is long, shortening of the working time is strongly demanded. Since only one surface in contact with the mold is heated, distortion due to a difference in heat shrinkage is likely to occur inside the molded article, and the quality is inevitably deteriorated accordingly.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems, and a method of molding a fiber-reinforced plastic molded article according to the first invention is to provide a thermosetting resin between holding films. A sheet material is formed by disposing a fiber reinforced material impregnated with the heat-pressurized air, and the sheet material is press-bonded to the cavity surface of the heating mold by hot compressed air. It is characterized in that the sheet material is heated from both sides and thermally cured.

[0005] A molding apparatus for a fiber-reinforced plastic molded article according to the second invention forms a sheet material in which a fiber-reinforced material impregnated with a thermosetting resin is disposed between holding films. A heating die and a pressurized air box are opposed to each other with a sheet material as a boundary, and a heated compressed air supply mechanism for supplying heated compressed air for pressing the sheet material to a cavity surface of the heating die is arranged in the pressurized box. It is characterized by being provided and configured.

Further, the molding apparatus for a fiber-reinforced plastic molded product according to the third invention is characterized in that an air release mechanism capable of appropriately holding the pressure in the compressed air box is provided. is there.

[0007]

A sheet material comprising a fiber reinforced material impregnated with a thermosetting resin interposed between holding films is pressed against the cavity surface of a heating mold by heating and compressed air. The material is heated from both sides by the heat of the heated compressed air and is thermally cured.

[0008]

1 to 4 show an embodiment of the present invention, in which reference numeral 1 denotes a sheet material, for example, an unsaturated sheet between a holding film 2a and 2b made of a thermoplastic resin such as polyvinyl chloride. A fiber reinforced material 4 made of, for example, a glass fiber mat impregnated with a gel-like thermosetting resin 3 such as a polyester resin is disposed, and the periphery thereof is sealed with an adhesive tape or the like to form a flexible sheet as a whole. ing.

As the holding films 2a and 2b, thermoplastic resins such as polyvinyl chloride, polyethylene and polypropylene are employed. As the thermosetting resin 3, unsaturated polyester resin, phenol resin, epoxy resin, melamine resin, urea A thermosetting resin such as a resin may be used.

As the fiber reinforcing material 4, glass fiber is usually used. However, carbon fiber, aramid fiber, etc. may be used. Roving may be used.

Reference numeral 5 denotes a heating die, which has a cavity surface 5a corresponding to a molded product, and a plurality of small exhaust holes 5b formed in the cavity surface 5a. A heater 6 and a heating pipe through which hot water passes are built in, and the heating mold 5 is heated.

Reference numeral 7 denotes a clamp mechanism, which is configured to be able to release the peripheral portion of the sheet material 1 by pressing and holding it by a pair of upper and lower members.

Reference numeral 8 denotes a compressed air box, which is provided opposite to the heating die 5 with the sheet material 1 as a boundary, and a heated compressed air supply mechanism 9 for supplying heated compressed air A is connected to the compressed air box 8. .

The heating / compressed air supply mechanism 9 comprises a compressed air generating section 9a and an air heating section 9b. The compressed air sent from the compressed air generating section 9a formed of, for example, a compressor is converted into air generated by a heater for generating hot air, for example. It is configured to be heated by the heating unit 9b.

Reference numeral 10 denotes a preparation heater, which in this case comprises a plurality of far-infrared heaters, and is provided between the upper part of the heating die 5 and the compressed air box 8 so as to be inserted or retracted.

Reference numeral 11 denotes an air release mechanism, which comprises a pressure gauge 11a and a throttle valve 11b. The pressure in the compressed air box 8 is confirmed by the pressure gauge 11a, and the heated compressed air supplied to the compressed air box 8 is provided. A is discharged from the throttle valve 11b to the outside to form a flow system for the heated compressed air A, and the pressure in the compressed air box 8 is adjusted by adjusting the opening degree of the throttle valve 11b. It is configured to maintain an appropriate pressure suitable for the material 1 and the like.

Since this embodiment has the above structure, first, as shown in FIG. 1, a gel-like thermosetting resin such as an unsaturated polyester resin is provided between the holding films 2a and 2b made of a thermoplastic resin such as polyvinyl chloride. A fiber reinforced material 4 made of, for example, a glass fiber mat impregnated with a resin 3 is disposed, and the periphery thereof is sealed with an adhesive tape to form a flexible sheet material 1 as a whole.

Next, as shown in FIG. 2, the sheet material 1 is disposed above the heating die 5, and the peripheral portion of the sheet material 1 is clamped and held by the clamp mechanism 7.

When the sheet material 1 is clamped by the clamp mechanism 7, as shown in FIG. 3, the preparatory heater 10 moves forward and is inserted between the upper part of the heating die 5 and the compressed air box 8 and heats. The mold 5 rises and stops, and the sheet material 1 is heated by the preparation heater 10 so that the holding films 2a and 2b made of thermoplastic resin are softened.
Since the sheet material 1 is in a gel state, the sheet material 1 comes into contact with the heating mold 5, and then the preparation heater 10 retreats and retreats.

Next, the compressed air box 8 descends, and the peripheral portion of the sheet material 1 is sandwiched between the heating mold 5 and the compressed air box 8.
In this state, the heated compressed air A is supplied from the heated compressed air supply mechanism 9 as shown in FIG. 4, and the sheet material 1 is pressed against the cavity surface 5a of the heating mold 5 by the heated compressed air A. Is heated from both sides by the heat of the heated compressed air sent into the compressed air box 8 from the heating mold 5 and the heated air supply mechanism 9, and the pressing and heating are continued until the sheet material 1 is hardened, and the sheet material 1 is hardened Thereafter, the supply of the heated compressed air A is stopped and the compressed air box 8 rises, then the heating mold 5 descends and is released, releasing the clamp mechanism 7 and taking out the semi-molded product W. The holding films 2a and 2b are peeled from the semi-molded product and trimmed by a conventional method to obtain a molded product.

The sheet material 1 in which the fiber reinforced material 4 impregnated with the thermosetting resin 3 is disposed between the holding films 2a and 2b as described above is heated by the heated compressed air from the heated compressed air supply mechanism 9. Is pressed from both sides by the heat of the heating mold 5 and the above-mentioned heated and compressed air and is thermoset in this pressed state, so that the reproducibility of the mold is improved, and the appearance and outer shape accuracy are improved. A good fiber-reinforced plastic molded product can be obtained, and when the sheet material 1 is heated, one surface of the sheet material 1 is
And the other surface of the sheet material 1 can be heated by the heat of the heated compressed air A. Therefore, both surfaces of the sheet material 1 can be heated at the same time, and the heat curing time can be shortened accordingly. Work efficiency can be improved, and since both surfaces of the sheet material 1 are heated, the occurrence of distortion due to a difference in heat shrinkage can be suppressed,
Since the quality of the molded article W can be improved and the structure uses heated compressed air, the equipment cost can be reduced and the economic efficiency can be improved.

At this time, since the air release mechanism 11 is provided, the heated compressed air A supplied to the compressed air box 8 is discharged to the outside from the throttle valve 11b to be heated.
And the throttle valve 11b
The pressure in the compressed air box 8 is increased by adjusting the opening degree of the heating die 5.
In addition, the pressure can be maintained at an appropriate pressure according to the size of the pressurized air box 8 and the material of the sheet material 1 and the like, so that the press-fitting and heating operations can be performed favorably.

A vacuum generator is connected to the exhaust hole 5b formed in the heating die 5 of the above embodiment, and the compressed air supply mechanism 9
When the compressed air A is supplied to press the sheet material 1 against the cavity surface 5a of the heating mold 5, the inside of the cavity is made to be in a negative pressure state by this vacuum generator, and the pressure of the sheet material 1 onto the cavity surface 5a is improved. It may be something.

The present invention is not limited to the above-described embodiment. In particular, the structure of the heating / compressed air supply mechanism 9 and the mounting structure to the compressed air box 8 are appropriately designed and changed. It can be applied to the structure without
Further, an auxiliary heater such as an infrared heater may be mounted above the inside of the compressed air box 8 to heat the compressed air box 8 by the heat of the auxiliary heater in addition to the heat of the heated compressed air. .

[0025]

As described above, the method and apparatus for molding a fiber-reinforced plastic molded article according to the present invention are as described above, wherein a sheet material in which a fiber-reinforced material impregnated with a thermosetting resin is arranged between holding films is heated and compressed. It is pressed against the cavity surface of the heating die by the heated compressed air from the air supply mechanism, and in this pressed state, it is heated from both sides by the heat of the heating die and the above-mentioned heated compressed air to be thermoset, so that the reproducibility of the die is improved. It is possible to obtain a fiber-reinforced plastic molded product having a good appearance and a good outer shape accuracy, and when heating the sheet material, heat one surface of the sheet material by the heating mold and the other surface of the sheet material. It can be heated by the heat of the heated compressed air, so that both sides of the sheet material can be heated at the same time, making it possible to shorten the heat curing time. Efficiency can be improved, and the occurrence of distortion due to the difference in heat shrinkage can be suppressed because both sides of the sheet material are heated, the quality of the molded product can be improved, and a structure using heated compressed air can be achieved. Therefore, the equipment cost can be reduced and the economic efficiency can be improved.

At this time, since the air release mechanism is provided, the heated compressed air supplied to the compressed air box can be discharged from the compressed air box to the outside to form a heating compressed air flow path system. At the same time, the pressure in the pressurized air box can be maintained at an appropriate pressure according to the size of the heating die and the pressurized air box, the material of the sheet material, and the like.

As described above, the intended purpose can be sufficiently achieved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a sheet material according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a molding step according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a molding step according to an embodiment of the present invention.

FIG. 4 is an explanatory view of a molding step according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet material 2a Holding film 2b Holding film 3 Thermosetting resin 4 Fiber reinforcement 5 Heating mold 5a Cavity surface 8 Compressed air box 9 Heated compressed air supply mechanism A Heated compressed air

Claims (3)

(57) [Claims] 1. A sheet material is formed by disposing a fiber reinforced material impregnated with a thermosetting resin between holding films, and the sheet material is press-bonded to a cavity surface of a heating mold by heating and compressed air. A molding method for a fiber-reinforced plastic molded product, wherein the sheet material is heated from both sides by heat in the heated compressed air and the heat of the heating mold in a state. 2. A sheet material in which a fiber reinforced material impregnated with a thermosetting resin is disposed between holding films, and a heating die for heating and curing the sheet material and a pressurized box are separated by the sheet material. A heated compressed air supply mechanism for supplying heated compressed air for pressing the sheet material to the cavity surface of the heating mold in the compressed air box. Molding equipment. 3. An apparatus for molding a fiber-reinforced plastic molded product according to claim 2, further comprising an air release mechanism capable of appropriately holding the pressure in said compressed air box.