JP3482664B2 - Molding method of reinforced plastic molding - 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 for molding a reinforced plastic molded product, and more particularly to a method for molding a large container-shaped molded product.

[0002]

2. Description of the Related Art As a conventional method for molding a reinforced plastic, for example, Japanese Patent Publication No. 59-36848 shown in FIGS. 1 and 2 is used.
The method described in Japanese Patent Publication is known. That is, it is a method for molding a fiber-reinforced plastic molded article, which comprises curing and molding a synthetic resin within a molding interval formed between a lower mold and an upper mold.

However, when molding a molded product in the form of a large container in which the shape of the molded product is required to have chemical resistance and boiling resistance by the above method, that is, a gel coat layer is required on the inner surface of the molded product. If you try to mold a large container-shaped molded product that
The pointed surface of the convex upper mold 2 in the figure is turned upside down, the gel coat is applied and cured, the upper mold is turned over again and turned down, and then the reinforcing fibers 11 and When the mold is fitted to the lower mold 1 on which an insert material is laid and an attempt is made to inject a synthetic resin from the injection port 9 at the center of the upper mold in FIG. 1, the gel coat layer cannot be injected. The drawback was that a reinforced plastic molding could not be obtained.

When a molded article which does not require a gel coat layer is to be formed, the laying work of the reinforcing fiber 11 and the insert material on the concave lower mold 1 is directed downward, and when it is out of reach. It is a laying work after entering the lower mold, and the reinforcing fiber 11 slips off and is displaced, which is troublesome. Further, when the mold is matched with the convex upper mold 2, the reinforcing fiber 11 is likely to slip off, and positioning of the insert material becomes difficult. The next resin injection work is also performed from the upper mold central portion 9 in FIG. 1, but since the position of the injection port is deep, it is necessary for an operator to sit on the upper mold and perform the injection work. The molded product thus obtained is not impregnated,
Defects such as bubbles occurred.

[0005]

DISCLOSURE OF THE INVENTION The object of the present invention is to prevent the slippage of reinforcing fibers and the provision of a gel coat layer, which are problems in the above-mentioned prior art when molding a large-sized container-shaped reinforced plastic molded product. It is to solve the drawbacks such as difficulty of injection of synthetic resin, workability of injection molding, non-impregnation of molded products and generation of bubbles.

[0006]

The present inventors have completed the present invention as a result of intensive research on the above problems. That is,
According to the present invention, by laying reinforcing fibers on the surface of the lower mold, covering the upper mold, and depressurizing the space portion formed by the elastic body provided in the interval between the entire peripheral portions of the upper mold and the lower mold. Mold clamp,
In a method of molding a reinforced plastic molded product, which comprises injecting a synthetic resin into a gap between molds and curing the same, an upper mold 32 is made of concave fiber reinforced plastic, a lower mold 31 is convex, and an opening of the molded product is made downward. Using a molding die, a plurality of space portions 45, 46 formed by elastic bodies 37, 38, 39 are provided on the entire peripheral edge of the die, and a plurality of suction ports 33, 34 are provided in the space portions.
A method for molding a reinforced plastic molded article, preferably a concave fiber, characterized in that a depressurizing suction port 35 for the mold gap is provided on the upper part of the concave upper mold 32, and a synthetic resin injection port 36 is provided on the peripheral edge of the concave upper mold 32. The upper mold 32 made of reinforced plastic has a thickness of 3 to 8 mm, and the flow of the injected synthetic resin can be seen, the speed at which the reinforcing fiber 43 of the injected synthetic resin is raised is 1 to 12 cm / min, the concave shape Provided is a method for molding a large container-shaped reinforced plastic molded product, in which the mold 32 has reinforcing members 47, 48 on the entire peripheral portion, side surface and upper portion.

The present invention will be described step by step with reference to the drawings.

A mold release agent, for example, a commercial product such as Free Coat FRP (product of Tomoe Kogyo Co., Ltd.) is usually applied to the convex lower mold 31 and the concave upper mold 32 shown in FIG. 4 to perform mold release treatment. . When molding a reinforced plastic molded product with an inner gel coat that requires chemical resistance and boiling resistance, a gel coat resin is applied and cured on the release-treated convex lower mold 31 to form a gel coat. A layer 42 is provided. The resin for the gel coat layer is preferably an unsaturated polyester or vinyl ester resin resin composition.

Hardened gel coat on the convex lower mold 31 of FIG.
Reinforcing fibers 43 are further laid on the toe layer, and insert materials 40 and 41 are laid on this using a positioning jig (usually made of fiber reinforced plastics). Further, the convex lower mold 31 is covered with the concave upper mold 32 suspended by a crane or the like. When the gel coat resin layer 42 is unnecessary, the reinforcing fiber 43 and the insert members 40 and 41 may be laid on the mold-released convex lower mold 31 and the concave upper mold 32 may be covered.

Subsequently, the concave upper mold 32 and the convex lower mold 3 shown in FIG.
1. The plurality of space portions 45, 46 formed by the elastic bodies 37, 38, 39 provided on the entire peripheral edge of the suction port 33, 3 are connected to the suction ports 33, 3.
4, the pressure is reduced by a vacuum pump or the like, and the concave upper mold 32 and the convex lower mold 31 are clamped. The synthetic resin liquid is injected from the synthetic resin injection port 36 provided in the peripheral portion of the concave upper mold 32. At this time, the vacuum suction port 35 provided in the upper part of the concave upper mold 32 is vacuumed while adjusting the adjusting valve 44. Impregnation is performed with a pump so that the rate of impregnation of the synthetic resin liquid into the reinforcing fibers is preferably 2 to 8 cm / min. In the impregnation and defoaming work, the concave upper mold 32 is made of fiber reinforced plastics, and its thickness is important for visually recognizing the impregnated state and the bubble generation state from the outside. Next, the synthetic resin is cured. After curing, the concave upper mold 32 is removed, and the reinforced plastic molded product obtained by demolding from the convex lower mold 31 is
It is a molded product without defects such as non-impregnation and bubbles.

The large-sized container-shaped molded product referred to in the present invention means a vertical 1
˜3 m × width 1-3 m × depth 40-200 cm, which is a container such as a bath, a septic tank or a tank.

The convex lower mold 31 shown in FIG. 4 is generally a resin mold made of fiber reinforced plastic used in hand-up, spray-up and resin transfer molding (RTM) molding methods. , Iron plate type, nickel electroforming mold whose surface layer is made of nickel, nickel +
An electroforming mold made of copper, a ZAS mold, or a mold may be used. Also, in these molds, a silicon rubber heater, nichrome wire,
By embedding hot water pipes, steam pipes, and the like so that the convex lower mold 31 can be heated, the molding cycle can be shortened. On the other hand, the concave upper mold 32 is made of fiber reinforced plastics and preferably has a thickness of 3 to 8 mm. Generally product area is 2
When it is smaller than m ^{2, the} thickness is preferably 3 to 5 mm, and when it is 2 m ² or more, the thickness is preferably 5 to 8 mm.

Examples of the reinforcing fiber 43 used in the present invention include glass fiber, carbon fiber, aramid fiber, vinylon fiber, polyester fiber non-woven fabric, etc., and their shapes are long fiber, short fiber and mat. A cross-shaped one can be used. When the preform-like reinforcing fibers obtained by conforming these fibers to the product shape are used alone or in combination with the above-mentioned reinforcing fibers, the laying work of the reinforcing fibers is simplified and the workability is improved.

The insert materials 40 and 41 are also called core materials for sandwich structures and are used for the purpose of improving the rigidity and weight reduction of molded products, such as plywood and square wood, resin concrete, and urethane foam. Etc. are commonly used. Conventionally, the laying work of the reinforcing fibers 43 and the insert materials 40 and 41 is done by laying on the concave lower mold 1 of FIG. 1, and the work is directed downward. In the present invention, the work efficiency is improved because the insert materials 40 and 41 are laid on the convex lower mold 31 shown in FIG. Next, the convex lower mold 31 is covered with the fiber-reinforced plastic concave upper mold 32.

Further, in order to observe the impregnation of the injected synthetic resin and the defoaming state from the outside, an uncolored gel coat resin composed of unsaturated polyester resin and vinyl ester resin is used for the inner surface of the concave upper mold 32. Is desirable. The next layer is made of fiber reinforced plastic, and unsaturated polyester resin, vinyl ester resin, and epoxy resin are used as the matrix, and mat-shaped or cloth-shaped glass fiber is generally used as the reinforcing fiber. As a partial reinforcement, carbon fiber or aramid fiber may be used to the extent that they do not interfere with the impregnation of the injected resin and the observation of the defoamed state.

Further, reinforcing members 47, 48 such as plywood, urethane foam, iron angles, etc. are provided on the entire peripheral portion, side surfaces, and upper portion.
have. When these are reinforced on the side surface and the upper surface, it is necessary to consider so as not to interfere with the impregnation of the injected synthetic resin and the observation of the defoamed state. In the prior art, the work of covering the concave upper mold 32 is performed by covering the reinforcing fibers laid on the concave lower mold 1 of FIG. It is very troublesome, and it causes non-impregnation and foam generation.

In the present invention, the reinforcing fibers 43 and the insert members 40, 41 laid on the convex lower mold 31 do not slip or shift, which is very simplified.

Next, a plurality of space portions 4 formed by the elastic bodies 37, 38, 39 in the spaces 45, 46 at all the peripheral edges of the mold.
The pressure of the nozzles 5 and 46 is reduced through the suction ports 33 and 34, and the gap width between the concave upper mold 32 and the convex lower mold 31 is set to a predetermined size.
A spacer 49 may be arranged outside the entire peripheral portion in order to confirm that the size is a predetermined size. The elastic body referred to here is so-called rubber or elastomer, for example, styrene-butadiene rubber, butadiene rubber, isoprene rubber,
Nitrile rubber, butyl rubber, chloroprene rubber, acrylic rubber, polyurethane rubber, fluororubber, silicone rubber, natural rubber are used, and the installation location may be the concave upper mold 32 or the convex lower mold 31.

Further, in order to make the gap width between the concave upper mold 32 and the convex lower mold 31 a predetermined size, a plurality of space portions 45,
46 is provided, and it is necessary to reduce the pressure at the plurality of suction ports 33, 34 by using a vacuum pump. Preferably, two or three space portions are provided, and the pressure can be reduced from the suction port 35 to sufficiently achieve the purpose.

After the mold is clamped, the upper part of the concave upper mold 32 is controlled so that the rising speed of the synthetic resin injected at the mold interval is preferably 1 to 12 cm / min from the synthetic resin injection port 36 provided in the peripheral portion of the concave upper mold 32. While the pressure is reduced from the pressure reducing suction port 35 provided in, the pressure is adjusted by the pressure reducing adjustment valve 44, and impregnation, defoaming, and curing are performed. The rising speed of the injected synthetic resin is an important factor for obtaining a molded product free from defects such as non-impregnation and bubbles, and particularly preferably 2 to 8 cm / min.

The synthetic resin used in the present invention is an unsaturated polyester resin, vinyl ester resin, epoxy resin,
Examples thereof include phenol resin and urethane resin, and a colorant, an inorganic filler, and a lightweight filler may be added to these resins as needed.

Conventionally, the synthetic resin is injected from the center 9 of the convex upper mold shown in FIG. 1, but when chemical resistance and boiling resistance are required, that is, a gel coat layer is required on the inner surface of the molded product. When a large container-shaped molded article is to be formed, the convex upper mold 2 is reversed, the gel coat is applied and cured, and the upper mold is reversed, and then the reinforcing fiber 11 and the insert material 40 are preliminarily used. , 41
It is necessary to perform mold matching with the lower mold 1 laid with the above, and to inject the synthetic resin from the injection port 9. Since there is a gel coat layer, the injection is impossible and the desired reinforced plastic molded product cannot be obtained. . In addition, since the injection work of the molded product which does not require the gel coat layer is performed from the central portion 9 of the upper mold, the troublesome injection work on the upper mold 1 is performed.

The synthetic resin inlet 36 of FIGS. 3 and 4 of the present invention.
Is provided on the peripheral portion of the concave upper die 32, and thus is a very simplified work as compared with the prior art. Further, the present invention is not restricted by the number of synthetic resin injection ports 36, but it is preferable to provide an even number on the diagonal. Preferably 2,
There are four.

In the present invention, the insert materials 40 and 41 are also used.
Conventionally, when laying, the glass fiber 11 for reinforcement is first laid on the concave lower mold, and the insert material is laid on the glass fiber 11. However, since the insert material is positioned, a person is placed in the lower mold. There is no choice but to position with a positioning jig, and at that time, the reinforcing fiber (glass fiber) inevitably slips or shifts, but in the present invention, such a problem occurs because it is laid on the convex lower mold 31. There are also advantages.

[0025]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.
In the following, all parts and% are based on weight unless otherwise specified.

Example 1 (molding of FRP bath) (mold release treatment) After cleaning the mold surface of the 1800 × 1500 × 700 mm bath mold, a mold release agent (free coat FRP, Tomoe Kogyo product) was applied, and 50 It was dried at 30 ° C. for 30 minutes and treated with a release agent.

(Application of gel coat resin) 100 parts of unsaturated polyester resin for gel coat GC-560 (manufactured by Dainippon Ink and Chemicals, Inc.), pigment POLYTON J-
107A (manufactured by Dainippon Ink and Chemicals, Inc.) 10 parts,
6 parts of cobalt naphthenate 0.4 parts and 55% methyl ethyl ketone peroxide 1.0 parts were mixed and applied to a convex lower mold bath forming mold 31 to a thickness of about 0.4 mm, and then 3 at 50 ° C.
After curing for 0 minutes.

(Molding) On this, glass fiber surface mats and preform mats as reinforcing fibers are laid on the convex lower mold bath mold 31 coated with gel coat, and then the insert materials 40 and 41 are used for positioning jigs. Laid using. Then, a concave upper mold 32 made of fiber reinforced plastics having a thickness of 5 mm, which was hung down by a crane, was placed thereon.

Subsequently, silicon rubber elastic bodies 37, 38 provided on the entire peripheral portions of the concave upper mold 32 and the convex lower mold 31.
A plurality of space portions 45 and 46 formed by 39 were decompressed from the suction ports 33 and 34 by a vacuum pump, and the concave upper mold 32 and the convex lower mold 31 were clamped. Concave upper mold 32
1.0 part of acetylacetone peroxide was mixed with 100 parts of unsaturated polyester resin "Polylite PC-202-LV" (manufactured by Dainippon Ink and Chemicals, Inc.) through a synthetic resin injection port 36 provided in the peripheral portion of The resin composition prepared is injected. At this time, the pressure reducing suction port 35 provided on the upper portion of the concave upper mold 32 was impregnated while adjusting the adjusting valve 44 so that the impregnation rising rate of the injected resin composition was 5 cm / min. The foamed portion was hit visually with a mallet or the like to defoam it, confirm that there was no foam, and then cure.

After demolding, a bath having a depth of 60 cm was obtained in which the gel coat layer and the FRP layer were integrated. The obtained bath does not have any impregnation and no bubble portion, and satisfies the performance of JIS A 5712 (Bath with glass fiber reinforced polyester washing place), there is no deviation of the reinforcing fiber, and the gel coat layer is easily provided. It was effective in improving the molding workability.

[0031]

According to the present invention, the concave upper mold 32 is made of concave fiber reinforced plastic, the convex lower mold 31 is convex, and the opening of the molded product is placed downward. A plurality of space portions 45, 46 formed by the elastic bodies 37, 38, 39 are provided at intervals, a plurality of suction ports 33, 34 are provided at the space portions, and depressurization suction ports 35 at the die intervals are provided above the concave upper die 32. And a synthetic resin injection port 36 are provided in the peripheral portion of the concave upper mold 32 to mold a large container-shaped reinforced plastic molded product, and a reinforced plastic molded product with a gel coat that requires chemical resistance and boiling resistance. The product can be easily molded, and even when molding a reinforced plastic molded product without gel coat, there is no slippage or displacement of the reinforcing fiber, positioning of insert material and injection work are very simple, and no impregnation or foaming occurs. For molding workability such as obtaining a molded product that does not have The is intended.

The present invention is extremely useful for molding a reinforced plastic molded product in the form of a large container, such as a bathtub or a bath for a molded product with a gel coat, and a septic tank for a molded product without a gel coat.

[0033]

[Brief description of drawings]

FIG. 1 is a front view of a conventional method for molding a reinforced plastic molded product.

FIG. 2 is a cross-sectional view of a conventional method for molding a reinforced plastic molded product.

FIG. 3 is a front view showing an embodiment of a method for molding a molded product according to the present invention.

FIG. 4 is a cross-sectional view showing an embodiment of a method for molding a molded product according to the present invention.

[Explanation of symbols]

1: Lower mold 2: Upper mold 3,4: Rubber tube to which internal pressure is applied 5: Suction suction port leading to the sealing space 6: Rubber packing 7: Sealing interval 8: Suction suction port leading to the molding interval 9: synthetic resin injection port 10: Backing spacer 11: Glass fiber for reinforcement 31: Convex lower mold 32: concave upper mold 33, 34: Decompression suction port (for mold clamping) 35: Suction port for decompression (for impregnation and defoaming) 36: Synthetic resin injection port 37, 38, 39: Elastic body 40: Insert material (plywood) 41: Insert material (square material) 42: Gel coat resin layer 43: Reinforcing fiber 44: Pressure reducing adjustment valve 45, 46: Space portion 47: Reinforcement material 48: Reinforcement material 49: Spacer

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 70/00-70/88 B29C 39/00-39/44

Claims (5)

(57) [Claims] 1. A method of laying reinforcing fibers on the surface of a lower mold, covering the upper mold, and decompressing a space portion formed by an elastic body provided at a space between all peripheral edges of the upper mold and the lower mold. In the method of molding a reinforced plastic molded product, which comprises:
Is a concave mold made of fiber reinforced plastic, the lower mold 31 is convex and the opening of the molded product is downward, and the space parts 45, 46 formed by the elastic bodies 37, 38, 39 on the entire peripheral edge of the mold.
A plurality of suction ports 33, 34 are provided in the space, a suction port 35 for depressurizing the mold gap is provided above the concave upper mold 32, and a synthetic resin injection port 36 is provided at the peripheral edge of the concave upper mold 32. A method for molding a reinforced plastic molded article, which is characterized by being provided. 2. The method for molding a reinforced plastic molded product according to claim 1, wherein the molded product has a large container shape. 3. The method for molding a reinforced plastic molded article according to claim 1, wherein the concave fiber reinforced plastic upper die 32 has a thickness of 3 to 8 mm and the flow of the injected synthetic resin is visible. 4. The method for molding a reinforced plastic molded article according to claim 1, wherein the speed at which the reinforcing fiber 43 of the injected synthetic resin is raised is 1 to 12 cm / min. 5. The method for molding a reinforced plastic molded product according to claim 1, wherein the concave upper mold 32 has reinforcing members 47, 48 on the entire peripheral edge, side surface and upper part.