JP3166562B2 - Method and apparatus for molding fiber reinforced plastics having a thermoplastic material on the surface - 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 fiber reinforced plastics (hereinafter referred to as FRP) having a thermoplastic material on the surface.

[0002]

2. Description of the Related Art It is common practice to provide a gel coat layer as a design surface on a part of the surface of an FRP in order to improve aesthetics, surface protection, heat resistance, and the like. However, the gel coat coating operation has the following problems.
(1) When spraying a gel coat resin onto a molding die,
The gel coat resin becomes fine particles and scatters in the air, and the workplace of the gel coat coating machine and the surrounding environment,
Not only is it dirty, it is not good for environmental hygiene. (2) Further, the gel coat layer needs to be sprayed thinly and uniformly, and the gel coat application operation requires considerable skill.

[0003] Therefore, instead of providing a gel coat layer on the surface of the FRP, attempts have been made to coat the surface of the FRP with a thermoplastic resin film, sheet, or the like and to integrate the FRP with the FRP. For example, real-Open No. 1-68811
No., after laying a thermoplastic film in the molding die, filling the upper part of the thermoplastic film with a thermosetting resin containing a reinforcing material such as glass fiber, cured, molded, FRP of It discloses that a thermoplastic film layer is provided on the surface. Japanese Patent Application Laid-Open No. Hei 5-237924 discloses that an adhesive is applied to an FRP which has already been formed into a product shape, and a thermoplastic sheet is vacuum-formed and simultaneously integrated with the FRP to provide a thermoplastic resin layer on the surface. are doing.

[0004]

The object of the invention is to be Solved However, the real No. 1-6
In the method of No. 8811, a thin film having a thickness smaller than that of a sheet is used as a thermoplastic resin, and the film of the thermoplastic resin is closely adhered to a molding die by, for example, vacuum suction of the film or They are made to adhere to each other by attracting static electricity and attracting static electricity.However, if the film is simply placed in close contact with the molding die as described above, wrinkles may occur on the film during molding, The thickness varies considerably, and in some cases, the film is often damaged.

In the method disclosed in Japanese Patent Application Laid-Open No. Hei 5-237924, a thermoplastic sheet is preformed for this purpose. However, a step of making a hole in the FRP for vacuum forming the thermoplastic resin sheet, and an adhesive on the surface of the FRP An extra step and cost are required because an adhesive application step for applying the adhesive is required. Further, there are cases where the pores are closed by the application of the adhesive and the thermoplastic sheet cannot be vacuum formed. The present invention solves the above-mentioned conventional problems and provides an FRP having a thermoplastic material on its surface.
The molding method and apparatus, particularly, wrinkles of the thermoplastic material layer,
An object of the present invention is to provide a method and an apparatus for forming an FRP which are free from breakage and have excellent appearance.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that a thermoplastic sheet, which has been formed in the shape of an FRP molded product in advance, is formed into a male mold. After setting between the mold and the female mold, injecting a thermosetting resin and molding, it was found that wrinkles, breakage, etc. of the thermoplastic resin sheet on the molded product surface could be obtained, The present invention has been completed.

That is, the method of molding fiber-reinforced plastics of the present invention corresponds to the shape of a molded product to be molded between a male mold and a female mold of a pair of male and female molds. After placing the preformed thermoplastic sheet, placing the reinforcing fiber, closing the mold, injecting thermosetting resin, curing and molding, integrating the thermoplastic sheet on the molded product surface It is characterized by having.

At the time of closing the mold, the thermoplastic sheet placed between the male mold and the female mold of the molding die is fixed by the pinch-off portion of the molding die having a pinch-off portion. It is preferable to prevent the displacement of the plastic sheet.

In the method of molding fiber-reinforced plastics according to the present invention, the reinforcing fiber may be a preformed reinforcing fiber corresponding to the shape of the molded article to be molded. In the method of molding fiber-reinforced plastics according to the present invention, the thermoplastic sheet preformed in accordance with the shape of the molded article to be molded is preformed by vacuum molding using a molding die having a vacuum molding function. Thermoplastic sheet may be used.

At the time of closing the mold, the thermoplastic sheet placed between the male mold and the female mold of the molding die is fixed by the pinch-off portion of the molding die having a pinch-off portion. It is preferable to prevent the displacement of the thermoplastic sheet.

[0011] The molding apparatus for fiber-reinforced plastics according to the present invention comprises a pair of a male mold and a female mold, and a molded product to be molded is formed between the male mold and the female mold of a molding mold having a pinch-off portion. Place the preformed thermoplastic sheet according to the shape of the above, place the reinforcing fiber, close the mold, inject the thermosetting resin, cure and mold, the thermoplastic sheet on the molded product surface In a molding apparatus for fiber-reinforced plastics, which is made to have an integrated, a pinch-off portion of the molding die is provided with a plurality of sets of abutting members for fixing the thermoplastic sheet therebetween. I do.

[0012]

According to the method for producing fiber-reinforced plastics of the present invention, a preformed thermoplastic sheet is set, and then reinforcing fibers are set, and a liquid thermosetting resin is injected to cure and mold. Therefore, the injected thermosetting resin penetrates into the reinforcing fiber, impregnates the entire reinforcing fiber, and after the thermosetting resin reaches the thermoplastic sheet surface, the thermosetting resin is cured and molded. Therefore, a molded article having a thermoplastic sheet on its surface, and a molded article obtained by impregnating a reinforcing fiber with a thermosetting resin and curing inside the molded article are obtained. No special adhesive is required for bonding the thermoplastic sheet on the surface of the molded product. Moreover, since the thermoplastic sheet used as the surface of the molded article is preformed, no excessive pressure is applied at the time of molding, and no wrinkling or breakage occurs. Further, at the time of the mold clamping, by fixing the thermoplastic sheet placed between the male mold and the female mold of the molding die with the pinch-off portion of the molding die having a pinch-off portion, during molding. The displacement of the thermoplastic sheet can be prevented. Further, by disposing a plurality of abutting members for fixing the thermoplastic sheet in between at the pinch-off portion of the molding die, it is possible to prevent the thermoplastic sheet from shifting.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory cross-sectional view showing the method of the present invention. As shown in FIG. 1, the method of the present invention employs a male mold 1 and a female mold 2 of a pair of molding dies 1 and 2 as shown in FIG. In the meantime, the thermoplastic sheet 3 and the reinforcing fiber 4 preformed according to the shape of the molded article to be molded are placed, and after closing the mold, a thermosetting resin is injected from the injection port 5. What is necessary is just to carry out hardening molding, opening a mold, and taking out a molded product. As the molding die used in the present invention, a known molding die used for resin transfer molding and the like can be used.

Displacement of the thermoplastic sheet 3 during molding,
In order to further prevent wrinkles and breakage, a method of strongly fixing with a molding die as shown in FIGS. 2 and 3 can be used. Generally, various pinch-off structures are provided in the periphery of the engagement between the male mold 1 and the female mold 2 of the molding die in order to suppress the outflow of the liquid thermosetting resin during molding. The pinch-off structure shown in FIGS. 2 and 3 is generally called a soft pinch structure. FIG. 3 is a cross-sectional view showing a main part of the pinch-off portion. An elastic rubber 6 having a square cross-section is provided along the pinch-off portion so as to make a loop around the outer peripheral portion of the female mold 2. ing. In such a soft pinch structure using the elastic rubber 6, the thermoplastic sheet 3 is strongly sandwiched between the male mold 1 of the molding die and the elastic rubber 6, and the elastic rubber 6 is applied to the male mold 1. The thermoplastic sheet 3 can be fixed by the pressing force.

In the molding die, FIG.
Even if a molding apparatus having a soft pinch structure is used as shown in FIG.
Wrinkles and breakage can also be prevented. Female mold 2 is shown in FIG.
(A) As shown in the plan view of FIG. 4 (b), the male mold 1 has 7a for the female mold 2 and 7b for the male mold 1 as abutting members. It is provided at a plurality of locations along the soft pinch portion. Butt members 7a, 7b
The abutment member provided on the surface where the female mold 2 and the male mold 1 face each other as a mold functions as a set. FIG. 5 (a),
FIG. 4B shows a case where the thermoplastic sheet 3 and the reinforcing material fiber 4 are placed between the male mold 1 and the female mold 2, respectively, in the planes AA and BB in FIGS. 4A and 4B. 3 shows a cross section. FIG.
As shown in (a), a butting member 7a is provided between the elastic rubbers 6a and 6b of the female die 2, and a butting member 7b is provided on the male die 1 so as to face the same. At that time, the thermoplastic sheet 3 is sandwiched between the abutting members 7a and 7b,
Fixed.

The abutment members 7a and 7b have a substantially rectangular shape, and there is no particular limitation on the material thereof, and a metal such as iron, stainless steel, or copper can be used. To attach the butting members 7a and 7b to the soft pinch,
Depressions are provided in the soft pinch portions of the male mold 1 and the female mold 2, respectively.
What is necessary is just to stop the abutting members 7a and 7b in a dent with a bolt etc.

An abutment member 7 as shown in FIGS.
When molding using a molding die having a and 7b,
When the thermoplastic sheet 3 is placed between the male mold 1 and the female mold 2, the preformed thermoplastic sheet 3 is placed between a pair of abutting members 7 a and 7 b of the male mold 1 and the female mold 2. Sandwich
The male mold 1 and the female mold 2 are fixed to the molding die by strongly closing the mold. At this time, when the thermoplastic sheet 3 is sandwiched between the abutting members 7a and 7b, if the reinforcing material fiber 4 is also sandwiched, the fixing force is weakened. For example, as shown in FIG. 5A, the abutting members 7a, 7
b is where the abutment members 7a, 7b
It is good to make a cut in the position corresponding to. By injecting the thermosetting resin in this manner, FIGS. 5A and 5B
The liquid thermosetting resin injected in step (1) penetrates between the reinforcing fibers 4 and gradually reaches the soft pinch portion on the outer peripheral portion around the molding die, but the elastic rubber 6a of the soft pinch portion As a result, the flow of the thermosetting resin is stopped, and the air contained in the reinforcing material fibers 4 is extruded to be impregnated and defoamed. A small amount of the thermosetting resin that has not been pressed by the elastic rubber 6 a stays in the resin pool 8.

The type of the thermoplastic resin used as the thermoplastic sheet 3 in the present invention is not particularly limited as long as it can be vacuum formed. For example, polyalkyl methacrylate, polyamide, polyethylene, polypropylene, polyphenylene sulfide, polyvinyl chloride, Polystyrene, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or copolymers or graft resins or modified resins containing these resins as main components, such as ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, chloride Various thermoplastic resins such as vinyl-vinyl acetate copolymer, urethane-vinyl chloride copolymer, acrylonitrile-butadiene-styrene copolymer, maleic acid-modified polyethylene, and acrylic acid-modified polypropylene can be used. .

The thickness of the thermoplastic sheet 3 is not particularly limited, but is preferably 254 μm or more. 254μ
If it is less than m, the thermoplastic sheet 3 may be damaged or wrinkles may occur.

The type of the reinforcing fiber 4 in the present invention is not particularly limited as long as it is used for fiber reinforcement. For example, known fibers such as glass fiber, aramid fiber, carbon fiber and silicon fiber can be used. Inexpensive,
Since it is easily available, it can be preferably used.

As the kind of thermosetting resin for the matrix (base resin), known unsaturated polyester resin, epoxy resin, vinyl ester resin, polyurethane resin, phenol resin, etc. are used as resin for fiber reinforced plastics. However, unsaturated polyester resins are inexpensive and practical. As the thermosetting resin used in the present invention, a curing agent, a curing accelerator and the like are appropriately used together.

The preformed product of the thermoplastic sheet 3 used in the present invention can be obtained by using a conventionally well-known method. For example, after the thermoplastic sheet 3 is heated and softened, it is set in a vacuum forming apparatus and preformed to obtain a preformed product. Vacuum forming may be a combination of pressure forming. The preformed product of the thermoplastic sheet 3 may of course be a thermoplastic sheet 3 preformed by vacuum forming using a forming die having vacuum forming means. If a molding die having a vacuum forming means is used, the preliminary molding of the thermoplastic sheet 3 and the curing molding of the fiber reinforced plastics can be performed by one molding die. That is, as shown in FIG. 6, the thermoplastic sheet 3 and the reinforcing material fiber 4 are set in a molding die, the mold is closed, and the thermoplastic sheet 3 is preliminarily formed by vacuum forming by sucking air from the air suction holes 9. After molding, a thermosetting resin is injected and cured and molded, so that the thermoplastic sheet 3 can be integrally provided on the surface of the molded product.

The form of the reinforcing fiber 4 used in the present invention may be a mat, a woven fabric, a nonwoven fabric, or the like. Even if the reinforcing fiber 4 is preformed in the shape of a molded product,
Although it is not necessary, the preformed one can be preferably used because the reinforcing fiber 4 is less likely to be damaged during the formation. When using non-preformed reinforcing fiber 4,
What is called a preformable mat which is easy to preform is preferable.

(Experimental Example 1) A glass fiber mat (Glaspac GP-450, manufactured by Fuji Fiber Glass Co., Ltd., fiber diameter 10 μm) 3PLY as the reinforcing fiber 4, and an acrylic resin sheet ( (Mitsubishi Rayon Co., Ltd., Shinkolite A, thickness 3.0mm)
Was preformed into a product shape. These are placed between the male mold 1 and the female mold 2 using the molding die of FIG.
After closing the mold, unsaturated polyester resin as thermosetting resin (PC-202, manufactured by Dainippon Ink and Chemicals, Inc.)
Was injected, cured and molded, and the mold was opened to obtain a box-shaped fiber-reinforced plastic having a thermoplastic resin on the surface. The obtained fiber reinforced plastics has a thickness of 0.5
It has a surface layer of acrylic resin having a thickness of 3.5 mm to 3.0 mm, and has an overall thickness of 3.5 to 6.5 mm. Was not seen.

(Experimental Example 2) As a reinforcing material fiber 4, a glass fiber preform mat (manufactured by Nitto Boseki Co., Ltd., fiber diameter 10 μm, thickness 3.5 mm) was used.
Acrylic resin sheet (Mitsubishi Rayon Co., Ltd.)
(Shinkolite A, thickness 4.0 mm) was preformed into a product shape. These are placed between the male mold 1 and the female mold 2 using the molding dies shown in FIGS. 2 and 3, and after closing the molds, a vinyl ester resin (Dai Nippon Ink Chemical Industry Co., Ltd.) is used as a thermosetting resin. ), PC-304C) was injected, cured and molded, and the mold was opened to obtain a box-shaped fiber-reinforced plastic having a thermoplastic resin on the surface. The obtained fiber reinforced plastics has a surface layer of an acrylic resin having a thickness of 1.0 to 4.0 mm, and has an overall thickness of 4.0 to 4.0 mm.
It was 7.0 mm, and the acrylic resin on the surface was closely adhered to the molded article main body, and no wrinkles or damaged parts were observed.

(Experimental Example 3) A glass fiber preform mat (manufactured by Nitto Boseki Co., Ltd., fiber diameter 10 μm, thickness 2.5 mm) was used as the reinforcing fiber 4, and the thermoplastic sheet 3 was used.
Acrylic resin sheet (Mitsubishi Rayon Co., Ltd.)
(Shinkolite A, thickness 3.0 mm) was preformed into a product shape. These are placed between the male mold 1 and the female mold 2 using the molding dies shown in FIGS. 4 and 5, and after the molds are closed, an unsaturated polyester resin (Dainippon Ink and Chemicals, Inc.) is used as a thermosetting resin. Co., Ltd., PC-670C) was injected, cured, molded, and opened to obtain a box-shaped fiber-reinforced plastic having a thermoplastic resin on the surface. The obtained fiber reinforced plastics has a thickness of 0.5 to 2.0.
mm acrylic resin surface layer, the overall thickness is 2.
It was 5 to 4.5 mm, and the acrylic resin on the surface was closely adhered to the molded article main body, and no wrinkles or damaged parts were observed.

(Experimental Example 4) A glass fiber mat (Glaspac GP-450, manufactured by Fuji Fiber Glass Co., Ltd., fiber diameter 10 μm) 3PLY as the reinforcing fiber 4, and an acrylic resin sheet ( (Mitsubishi Rayon Co., Ltd., Shinkolite A, thickness 3.0mm)
It was used. These glass fiber mats and acrylic resin sheets, which were not preformed, were placed between the male mold 1 and the female mold 2 of the molding die having the vacuum forming means shown in FIG. Unsaturated polyester resin (PC-670C, manufactured by Dainippon Ink and Chemicals, Inc.) is injected as a reactive resin, cured, molded, opened, and box-shaped fiber reinforced plastics having a thermoplastic resin on the surface. I got
The obtained fiber-reinforced plastics has a thickness of 0.5 to
It has a 2.0 mm acrylic resin surface layer, the overall thickness is 2.5 to 4.5 mm, and the acrylic resin on the surface is closely adhered to the molded article main body. I couldn't see it.

[0028]

According to the method for molding fiber-reinforced plastics having a thermoplastic material on the surface thereof according to the present invention, since there is no gel coat spraying operation as in the prior art, there is no time occupied by the molding dies involved in gel coat spraying and the production time is reduced. Good nature. In the method of spraying with gel coat, a high level of surface smoothness of the mold is required, but the thermoplastic sheet using the preformed product according to the present invention is thermoplastic and does not shrink, so that the surface of the mold is smooth. Sex does not need to be that high.

In the fiber-reinforced plastics molding method of the present invention, a preformed thermoplastic sheet is set in a molding die, and then a thermosetting resin is injected and molded and cured. In addition, a wrinkled or damaged portion of the thermoplastic resin is not observed on the surface of the molded product, and a molded product obtained by closely bonding the thermoplastic resin sheet to the molded product main body is obtained. At this time, by fixing the thermoplastic sheet at the pinch-off portion of the molding die, a more preferable molded product can be obtained.

Further, according to the fiber-reinforced plastics molding method of the present invention, a thermoplastic sheet and a reinforcing fiber which are not preformed between a male mold and a female mold of a molding die provided with a vacuum molding means. To obtain a fiber reinforced plastics with a thermoplastic resin on the surface even if the thermoplastic sheet is preformed by vacuum pressure molding, clamped, injected with the thermosetting resin as it is, and cured and molded. Can be. According to this method, the fiber-reinforced plastics having the thermoplastic sheet integrated on the surface of the molded product can be continuously obtained only in one molding die, so that the productivity can be improved,
Expenses can be reduced.

When the molding apparatus of the present invention using the abutment member in the molding die is used, wrinkles and breakage of the thermoplastic sheet are not further observed, and a more preferable molded article is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing one embodiment of a molding method of the present invention.

FIG. 2 is an explanatory sectional view showing another embodiment of the molding method of the present invention.

FIG. 3 is an explanatory cross-sectional view of a main part of a pinch-off portion in the molding die of FIG. 2;

4 (a) is a plan view of a female mold in a fiber reinforced plastics molding apparatus using the abutment member of the present invention. FIG.
(B) is a plan view showing one embodiment of a male plan view.

FIG. 5 shows a pinch-off portion of the molding apparatus of FIG.
FIG. 3A is an explanatory cross-sectional view of a main part along a line AA, and FIG.

FIG. 6 is an explanatory sectional view showing still another embodiment of the molding method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Male type 2 Female type 3 Thermoplastic sheet 4 Reinforcement fiber 5 Injection port 6, 6a, 6b Elastic rubber 7a, 7b Butting member 8 Resin pool 9 Air suction hole

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FIB29L 9:00

Claims (4)

(57) [Claims] 1. A preformed thermoplastic sheet corresponding to the shape of a molded article to be molded is placed between a male mold and a female mold of a pair of male and female molds. After placing the reinforcing fiber and closing the mold, a thermosetting resin is injected, cured and molded, and in a molding method of fiber reinforced plastics in which a thermoplastic sheet is integrally provided on the surface of the molded product. The thermoplastic sheet preformed in accordance with the shape of the molded article to be molded is a thermoplastic sheet preformed by vacuum molding using the molding die having vacuum forming means. Of forming fiber reinforced plastics. 2. The molding of fiber reinforced plastics according to claim 1, wherein the reinforcing fiber is a reinforcing fiber preformed using the molding die in accordance with the shape of the molded article to be molded. Method. 3. A thermoplastic pre-formed according to the shape of a molded product to be molded between a male die and a female die of a molding die having a pair of a male die and a female die and having a pinch-off portion. After placing the sheet, placing the reinforcing fiber, closing the mold, injecting a thermoplastic resin, curing and molding, the fiber reinforced plastic sheet with the thermoplastic sheet integrated with the molded product surface In the molding apparatus of the above, in the pinch-off portion of the molding die,
An apparatus for molding fiber-reinforced plastics, comprising a plurality of sets of abutting members for fixing a thermoplastic sheet therebetween. 4. An apparatus for molding fiber reinforced plastics according to claim 3, wherein said molding die is provided with vacuum forming means for vacuum forming a thermoplastic sheet.