JPS6268729A - Molding of fiber reinforced plastic molding - Google Patents

Abstract

PURPOSE:To make it possible to mold a molding without any limitation of shape and thickness of the molding and to improve the processability, by tightly adhering a film on a mold for vacuum molding and thereafter laminating a fiber reinforced plastic on the film by means of hand lay-up. CONSTITUTION:A flexible film 2 is at first placed on a mold 1 for vacuum molding and air between the film 2 and the mold 1 for vacuum molding is then evacuated to adhere tightly the film 2 with the mold 1 for vacuum molding. FRP is then laminated on the film 2 by means of hand lay-up. On laminating FRP7, the film 2 has a roll of a releasing agent. As the mold 1 for vacuum molding and FRP7 are shielded each other by the film 2, fibrous materials such as glass fibers in FRP7 do not directly contact with the mold 1 for vacuum molding and it is therefore not necessary to form a gel-coat layer on the mold for vacuum molding.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a method for molding fiber-reinforced plastic molded products, and more specifically, to a method for molding a fiber-reinforced plastic molded product, and more specifically, a method for molding a fiber-reinforced plastic molded product, and more specifically, it relates to a method for molding a fiber-reinforced plastic molded product, and more specifically, it relates to a method for molding a fiber-reinforced plastic molded product, and more specifically, it relates to a method for molding a fiber-reinforced plastic molded product, and more specifically, it relates to a method for molding a fiber-reinforced plastic molded product, and more specifically, a method for molding a fiber-reinforced plastic molded product. The present invention relates to a method of molding plates and the like using fiber-reinforced plastic (hereinafter referred to as FRP), which is made by impregnating a fibrous material such as glass fiber with a thermosetting resin such as an epoxy resin.

[Conventional technology]

Because FRP has excellent strength, water resistance, chemical resistance, and other properties, a wide variety of products such as vehicle parts, prefabricated liquid storage tanks, decorative panels, and radio wave reflectors for parabolic antennas are made using it. . The method of molding these with FRP involves placing a fibrous material such as glass fiber on a mold, and repeatedly impregnating the fibrous material with a thermosetting resin such as epoxy resin using rollers, spacing, etc. The so-called hand lay-up method, in which the thermosetting resin is cured and then demolded, is conventionally known. Another method is to first cover both sides of an FRP sheet with a film to form an original sheet, place the original sheet on a vacuum forming mold, and then remove the air between the vacuum forming mold and the original sheet. A so-called vacuum forming method has also been proposed in which the original sheet is brought into close contact with a vacuum forming mold, and after the thermosetting resin is cured, the mold is removed.

[Problem that the invention seeks to solve]

When molding using the hand lay-up method described above, it is necessary to thoroughly polish the mold to make it a mirror surface, and after applying a mold release agent and curing it, apply a gel coat and let it harden. Not only is it time-consuming to wait until the process is completed, but the rotation rate of the mold is low, resulting in poor workability.

On the other hand, in the vacuum forming method described above, workability is improved compared to the hand lay-up method, but fibrous materials such as glass fibers may be cut during vacuum forming, and furthermore,
It is unsuitable for molding products with complex shapes or relatively thick walls. Another drawback is that the shape of the back side of the molded product cannot be freely selected, such as by providing reinforcing ribs and attachment parts.

The present invention solves the above-mentioned conventional drawbacks, and
By using the vacuum forming method and hand lay-up method together, it is possible to form any shape or wall thickness of the molded product, which not only improves workability but also provides FRP with excellent strength and appearance.
The present invention provides a method for molding a molded article.

[Means for solving problems]

In the present invention, first, a stretchable film is placed on a vacuum molding mold-F, and then the air between the film and the vacuum molding mold is removed to bring the film into close contact with the vacuum molding mold.

Thereafter, an uncured fiber-reinforced plastic obtained by impregnating composition m with an uncured liquid of a thermosetting resin is laminated on the film by a hand lay-up method. Furthermore, after the thermosetting resin is cured, it is characterized in that it is removed from the vacuum molding mold.

[Action of the invention]

□ In the method for molding an FRP molded product according to the present invention,
First, the air between the film and the vacuum molding mold is removed, and the film is brought into close contact with the vacuum molding mold.

This film, which adheres closely to the vacuum molding mold, gives the vacuum molding mold a mirror-like polished state, and moreover, this film plays the role of a mold release agent. In addition, the vacuum forming mold and the laminated FRP are blocked by the film, and the FRP
Since the fibrous materials such as glass fibers constituting the mold do not come into direct contact with the vacuum molding mold, there is no need to form a gel coat layer on the vacuum molding mold. Next, FRP is laminated on the film that is in close contact with the vacuum forming mold, so before laminating FRP, it is possible to check whether the film is accurately adhered to the vacuum forming mold, and in some cases, It is also possible to modify it. In addition, rather than covering both sides of the FRP with a film, the film is laminated using a hand lay-up method that adheres to the vacuum forming mold, allowing for adjustment of the wall thickness of the molded product and reinforcing ribs on the back side of the molded product. can be freely formed.

〔Example〕

Embodiments of the invention will now be described with reference to the accompanying drawings.

Figure 1 is an explanatory diagram of the state in which the film 1 is placed on a vacuum forming mold, Figure 2 is an explanatory diagram of the state in which the film is vacuum formed, and Figure 3 is an explanatory diagram of the state in which FRP is laminated on the film. The explanatory diagram, FIG. 4, is a partially cutaway perspective view of an FRP molded product molded according to the present invention.

In the method for molding an FRP molded article according to the present invention, as shown in FIG. 1, first, a stretchable film 2 is placed on a vacuum molding die l. The vacuum molding mold 1 has the size and shape of the FRP molded product to be molded, has a hole 3 for removing air, and a vacuum pump 4 is connected to each mold 3. This vacuum molding mold 1 does not need to be sufficiently polished to have a mirror surface like conventional molding molds, and it is sufficient if it has a generally smooth surface. The stretchable film 2 may be made of polyethylene, polypropylene, or other materials, but it is preferably one that will not be eroded or swollen by the resin composition impregnated into the FRP mlI material. This film 2 is cut into a size equal to the size of the vacuum forming die 1 plus the presser foot 5, and placed in the vacuum forming die 1.

Next, as shown in FIG. 2, the air between the film 2 and the vacuum forming mold 1 is removed, and the film 2 is brought into close contact with the vacuum forming mold 1. In order to bring the film 2 into close contact with the vacuum forming die 1, the presser foot 5 around the film 2 is pressed onto the vacuum forming die 1 using a jig 6, and the vacuum pump 4 is operated.

At this time, since the film 2 stretches along the mold surface of the vacuum forming mold 1, no wrinkles are formed. The state of adhesion of this film 2 is inspected, and if it is adhered exactly as in the vacuum forming mold 1, the process moves directly to the FRP lamination process. If the film 2 does not adhere accurately, correction is made and the process moves to the lamination process.

After the film 2 is accurately brought into close contact with the vacuum forming mold l as described above, FR is applied onto the film 2 as shown in FIG.
P7 is laminated by hand layup method. As the fibrous material used for FRP7, glass fiber, polypropylene fiber, carbon fiber, graphite fiber can be used, and
Thermosetting resins used for FRP7 include polyester resins and epoxy resins, and these resins may be blended with curing agents, pigments, and the like. To laminate FRP7 on film 2, first apply uncured epoxy resin onto film 2, then place a fibrous material such as glass fiber on top of it, and then apply uncured epoxy resin on top of it. After applying the liquid, a roller impregnates the fibrous material with the uncured liquid. Alternatively, the fibrous material may be placed directly on the film 2, and an uncured liquid of polyester resin may be applied to the film 2 using a spatula or a roller, and the fibrous material may be impregnated with the uncured liquid using a spatula or roller. At this time, if necessary, there are reinforcing ribs 8 on the back side.
will be established. Also, when molding a parabolic antenna, F
A reflective material is placed on the front side or middle layer of RP7. This F
When laminating RP7, the film 2 plays the role of a mold release agent, and the film 2 also acts as a vacuum molding mold l.
Since the FRP 7 and the FRP 7 are separated from each other, the fibrous material such as glass fiber of the FRP 7 does not come into direct contact with the vacuum forming mold l. After the thermosetting resin of the FRP 7 thus laminated is cured, it is removed from the vacuum molding mold 1. The thermosetting resin may be cured naturally. However, although not shown, it is preferable to provide a heating device within or above the vacuum molding mold to heat the vacuum molding mold, etc., because the thermosetting resin can be cured in a short time. After the thermosetting resin has hardened, the jig 6 is removed and the mold is removed. At this time, since the film 2 plays the role of a mold release agent, it can be demolded very easily.

Thereafter, the presser foot 5 around the film 2 is cut off to form an FRP molded product as shown in FIG. 4.

In addition, after demolding, the film 2 may be peeled off from the FRP 7 as well. Even when the film 2 is peeled off, the surface of the molded product remains smooth and has a good appearance.

〔Effect of the invention〕

As described above, in the present invention, the vacuum forming mold is brought into a mirror-polished state by the film closely attached to the vacuum forming mold, and moreover, this film plays the role of a mold release agent. In addition, the vacuum forming mold and the laminated FRP are blocked by the film, and the fibrous materials such as glass fibers that make up the FRP do not come into direct contact with the vacuum forming mold, so a gel coat layer is formed on the vacuum forming mold. There's no need. Therefore, there is no need to polish the vacuum molding mold to a mirror surface or apply a mold release agent or gel coat to the top surface, so there is no need for labor and the rotation rate of the vacuum molding mold is good, making one operation possible. performance is significantly improved. Furthermore, since it can be confirmed whether the film is accurately adhered to the vacuum molding mold, even complex-shaped molded products can be molded exactly as in the vacuum molding mold. Furthermore, since the FRP is laminated onto a tightly adhered film using the hand lay-up method, it is possible to freely adjust the wall thickness of the molded product, add reinforcing ribs, etc., and the FRP molding has excellent strength and appearance. It is something that you can get.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; Fig. 1 is an explanatory diagram of a film placed on a vacuum forming mold, Fig. 2 is an explanatory diagram of a film being vacuum formed, and Fig. 3 is an explanatory diagram of a film placed on a vacuum forming mold. to F
FIG. 4 is a partially cutaway perspective view of an FRP molded product molded according to the present invention. In the figure, 1 is a vacuum forming mold, 2 is a film, 5 is a presser foot for the film, 7 is FRP, and 8 is a reinforcing rib.

Claims (1)

[Claims] A stretchable film is placed on a vacuum forming mold, the air is removed between the film and the vacuum forming mold, and the film is brought into close contact with the vacuum forming mold. An uncured fiber-reinforced plastic impregnated with a fibrous material is laminated on the film using a hand lay-up method,
A method for molding a fiber-reinforced plastic molded product, which comprises removing the thermosetting resin from a vacuum mold after curing.