JPH03166922A - Method for molding frp - Google Patents

Abstract

PURPOSE:To obtain an FRP molded product excellent in mechanical strength and appearance by a method wherein the membranelike article airtightly sealed on the peripheral part of a mold is placed on the reinforcing fiber impregnated with a resin placed on the mold and the space parts between the mold, the reinforcing fiber impregnated with the resin and the membrane like article are brought to a reduced pressure state to perform pressure molding from the outside of the membranelike article. CONSTITUTION:A reinforcing fiber 5 impregnated with a resin is placed on a mold 1 and a pressure bag composed of a membranelike article is placed thereon and the circumference of the bag is brought to an airtight state by a seal material 3 to mount a press plate 2 to the mold 1. In this constitution state, the mold 1 is evacuated under vacuum from the vacuum exhaust port provided to a press plate 2 by a vacuum pump and the spaces between the mold 1, the reinforcing fiber 5 impregnated with the resin and the membranelike article are brought to a vacuum state and not only remaining air bubbles but also the excessive resin are excluded. In this case, compressed air is injected in the pressure bag composed of the membranelike article 4 from a compressed air injection port 6 to press the reinforcing fiber 5 impregnated with the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application Field>> The present invention relates to a method for molding fiber reinforced plastic (hereinafter referred to as FRP).

<Conventional technology> Conventional FRP1fj. Regarding the shape method, there is also a pressurized bag forming method using a bag-like thin film body.

<<Problems to be Solved by the Invention>> However, the conventional pressurized bag molding method cannot remove the air bubbles remaining between the resin and the reinforcing fibers or the air bubbles remaining in the corners of the uneven portion. For this reason, problems such as a decrease in the mechanical strength of the FRP due to the remaining air bubbles and poor appearance due to the air bubbles in the corners occur.

Further, there was a problem in that only by applying pressure from the outside, the resin excessively attached to the reinforcing fibers could not be removed, and the mechanical strength of the FRP could not be improved.

The present invention was made in view of these problems, and its purpose is to improve the mechanical strength of FRP and to obtain an FRP molded product with excellent appearance.

<<Means for Solving the Problems>> In order to achieve the above-mentioned object, the invention according to claim 1 provides a method for molding fiber-reinforced plastic, comprising: A process of placing a thin film-like material on the mold from above the fibers, which is hermetically sealed around the mold, and reducing the pressure in the space between the mold, the reinforcing fiber impregnated with resin, and the thin film-like material. and a step of press-molding the thin film-like material from the outside.

Further, the invention according to claim 2 is characterized in that the thin film-like material is pressurized from outside with pressurized air.

Furthermore, the invention according to claim 3 is characterized in that pressure is applied from the outside of the thin film-like material using a defoaming roller.

<<Function>> According to the present invention, air bubbles remaining between the reinforcing fibers are removed by reducing the vacuum between the mold, the resin-impregnated reinforcing fibers, and the thin film-like material. Atmospheric pressure (1 atm) is applied from the outside to extrude and remove excess resin.

In addition, when atmospheric pressure alone is insufficient as the pressure from the outside, by using pressurized air, bubbles and excess resin can be removed quickly and appropriately. Furthermore, the same effect can be obtained by using a defoaming roller instead of pressurized air.

<<Example>> Hereinafter, an example of the present invention will be described in detail based on the drawings.

What is shown in FIG. 1 is a sectional view of a mold showing the first embodiment of the present invention, in which reinforcing fibers 5 impregnated with resin are placed on the mold 1, and a thin film is placed on top of the reinforcing fibers 5 impregnated with resin. A pressurized bag consisting of a material 4 is placed, the surrounding area is made airtight with a sealing material 3, and a presser plate 2 is attached to a mold 1.

In the configuration as described above, vacuum suction is performed using a vacuum bomb or the like from the vacuum exhaust port 7 provided on the presser plate 2 to create a vacuum between the mold 1, the reinforcing fibers 5 impregnated with resin, and the thin film material 4. As a condition, remove any remaining air bubbles and also remove excess resin. In this case, by injecting pressurized air from the pressurized air inlet 6 into the pressurized bag made of the thin film-like material 4 and pressurizing the reinforcing fibers 5 impregnated with resin, air bubbles are removed and excess resin is removed. can be quickly removed.

What is shown in FIG. 2 shows a second embodiment of the present invention, and the difference from the above embodiment is that instead of applying pressure with pressurized air after depressurization, a defoaming roller 8 is used to apply pressure. Defoaming,
Excess resin is removed, and the same effects as in the above embodiment can also be obtained.

<<Effects of the Invention> Since this invention molds FRP using the above molding method, it is possible to reduce the amount of air bubbles remaining in FRP, and therefore, it is possible to improve the mechanical strength of FRP. In addition, since excess resin can be removed, the content of reinforcing fibers in FRP can be increased, and the mechanical strength of FRP can be further improved.

Furthermore, according to the method of the present invention, air bubbles in the corners can be removed at the same time, so that an FRP molded product with a good appearance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a mold part according to the method of the present invention, and FIG. 2 is a cross-sectional view of a mold part showing another embodiment of the method of the present invention. 1... Molding mold 2... Holding plate 3... Sealing material 4... Thin film material 5... FRP 6... Pressurized air inlet 7... Decompression exhaust port 8... Defoaming roller

Claims (1)

[Claims] 1. In a method for molding fiber-reinforced plastics, a thin film-like material that is airtightly sealed around the periphery of the mold is placed on the mold from above the resin-impregnated reinforcing fiber placed on the mold. , a step of reducing the pressure in the space between the mold, the reinforcing fiber impregnated with resin, and the thin film-like object, and a step of pressure-molding the thin film-like object from the outside. Characteristic FRP molding method. 2. The FRP molding method according to claim 1, wherein the thin film-like material is pressurized from outside with pressurized air. 3. The FRP molding method according to claim 1, wherein pressure is applied from the outside of the thin film-like material using a defoaming roller.