JPS63112121A - Manufacture of fiber reinforced plastic laminated sheet - Google Patents

Abstract

PURPOSE:To make it possible to perform low-pressure molding with simple apparatus and operation and, in addition, prevent resin-starved areas and residual bubbles from developing by a method wherein a heap produced by pinching laminated prepregs among a plurality of stiffening plates is covered by a film so as to be heated and pressurized with a press in the state that the interior of the film is kept under vacuum through evacuation in order to harden resin. CONSTITUTION:Laminated prepregs 5, which are pinched between copper foils, are pinched among a plurality of stiffening plates 3 so as to put one upon another. Next, the whole of the laminates is covered and enclosed in the form of a bag by a film 7, to which a vacuum hose 10 is provided. The laminates covered by the film 7 is pinched through cushion materials 2 between the hot platens 1 of a press. By evacuating the interior of the film 7, bubbles within and among the prepregs 5 are removed. By pressing and heater in the state just mentioned above, the resin in the prepreg 5 hardens and a plurality of copper-clad fiber reinforced plastic laminated sheets are manufactured. In the above-mentioned method, gas is removed and low pressure is enough for integral pressurizing and consequently no resin-starved area generates and also no residual bubble develops.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing an FRP laminate.

[Conventional technology]

FIG. 2 is a cross-sectional view showing a conventional method for manufacturing an FRP laminate using a multistage press, and shows an example of a method for manufacturing a body-attached FRP laminate. In the figure, (1) is a press heating plate, (2) is a cushioning material, (3) is a backing plate, (4) is a copper foil, (5)
is prepreg. The method for manufacturing FRP laminates using the above multi-stage press is to laminate prepreg (5) and copper foil (4).
Arrange this between multiple backing plates (3),
A high pressure of 40 to 100 kFC/cI112 is applied to flow the resin between the press heat plates (1) with cushioning materials (2) on the top and bottom, and this removes air bubbles and heats the resin to harden it. Manufactures FRP laminates.

3 to 5 are cross-sectional views showing a conventional method of manufacturing an FRP laminate using a vacuum press, and show an example of a method of manufacturing a general FRP laminate without body bonding.

Figure 3 shows a manufacturing method using an autoclave. In the figure, (6) is an autoclave, (7) is a film, (
8) is a trolley, (9) is a sealing material, and (10) is a vacuum hose. The method for producing FRP laminates using an autoclave is to cover the prepreg (5) stacked on a trolley (8) with a film (7) and pressurize it to 5 to 15 kHz/cI11" with an inert gas in an autoclave (6). At the same time, a vacuum is drawn from the vacuum hose (10), thereby removing air bubbles without causing the resin to flow, and curing the resin to produce an FRP laminate. Figures 4 and 5 show a manufacturing method using a multistage press. In FIG. 4, the space between the backing plates (3) is sealed with a sealing jig (11), and air bubbles are removed by drawing a vacuum from a vacuum hose (10).

Further, in FIG. 5, the entire press is sealed with a sealing jig (11), and air bubbles are removed by evacuation from the exhaust pipe (10).

[Problem that the invention seeks to solve]

However, in the manufacturing method shown in Figure 2, it is necessary to apply high pressure to flow the resin in order to remove air bubbles within or between the prepregs, and if too much resin is flowed, the measling,
Defects such as weave exposure occur due to lack of resin. In addition, in all of the models shown in Figures 3 to 5, the inside of the laminated prepreg is evacuated in advance, so there is no need to remove air bubbles by applying high pressure and flowing resin, and defects due to insufficient resin do not occur. Both methods require large-scale equipment, jigs, etc., and there is a problem that they cannot be easily applied to existing multi-stage presses.

This invention is intended to solve the above-mentioned problems, and provides a method for manufacturing FRP laminates that allows low-pressure molding using simple equipment and operations, and is less likely to cause defects such as insufficient resin or residual air bubbles. The purpose is

[Means for solving problems]

The method for producing an FRP laminate of the present invention is to cover the stacked prepregs sandwiched between a plurality of backing plates with a film, and heat and pressurize them with a press while keeping the inside vacuumed. This is a method of curing the resin.

[For production]

In the method for producing an FRP laminate of the present invention, the laminated prepregs are arranged between pads, covered with a film and sealed, and the interior is evacuated, thereby preventing the inside of the prepregs from flowing out or Air bubbles existing between the prepregs are removed. When the resin is cured by heating and pressurizing it in this state, an FRP laminate without resin defects and residual air bubbles is manufactured.

The method for manufacturing laminates by vacuum pressing, which involves covering only the prepreg layer including the backing plate with a film and evacuating the inside as described above, can be applied to any existing multi-stage press machine, and is not large-scale. There is no need to use equipment, jigs, etc.

〔Example〕

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, showing the case of manufacturing a body-attached FRP laminate.
) to (11) indicate the same or equivalent parts as in FIGS. 2 to 5.

The method for producing an FRP laminate is to first laminate prepregs (5), sandwich them between copper foils (4), and arrange them between a plurality of backing plates (3), as in the case of FIG.

Next, the entire laminate is covered and sealed with a film (7) in the form of a bag, and a vacuum hose (10) is provided. Considering strength, heat resistance, etc., as the film (7) used here, polyethylene terephthalate film, polyvinyl alcohol film, polyester (nylon) film, etc. are suitable for press conditions at low temperatures, e.g., 120°C or lower; Polyimide films, fluororesin (Teflon) films, etc. are suitable for pressing conditions at temperatures above .degree. To cover the laminate with the film (7), the laminate is placed inside the double-folded film (7), and the end faces are sealed by heat fusion, adhesive, etc. to seal. The laminate thus covered with the film (7) is sandwiched between the press hot platens (1) via the cushioning material (2). In this state, vacuum hose (
When the inside of the film (7) is vacuumed from 10), the air bubbles in and between the prepregs (5) are removed, so when pressurized and heated by the press hot plate (1), the prepregs (5) ) is cured to produce a plurality of body-attached FRP laminates at once.

In the above method, gas is released by evacuation, so pressurization is performed at a low pressure such as 5 to 15 kg/am for integration.
The FRP laminate obtained in this way will not have a resin shortage as the resin will not flow out due to pressure, and the air bubbles will be removed by vacuuming, so there will be no residual air bubbles. .

As another embodiment of the present invention, a film (
7) A method may be adopted in which the inside is evacuated, the page emptying opening is sealed after the pressure is reduced, and the vacuum pack is heated and cured, thereby increasing the efficiency of the vacuum pump.

In the above embodiments, the case of manufacturing a copper-clad FRP laminate has been described, but as shown in FIGS. 3 to 5, a general FRP laminate without a body laminate can also be manufactured in the same manner. Further, in the above embodiment, in order to completely remove the gas within the film (7), a communicating hole may be provided at the end of the backing plate (3), or a glass cloth or the like may be provided.

〔Effect of the invention〕

According to the present invention, the interior is vacuumed by covering with a film,
I decided to apply heat and pressure using a press.

The following effects can be obtained.

■Can perform low-pressure molding similar to conventional vacuum presses, and is less prone to defects due to insufficient resin or residual air bubbles.

■Since resin flow can be suppressed, there is no chance of damage to the press heating plate or caul plate due to resin adhesion.

■Since it can be manufactured using simple equipment and operations, the cost is lower than that of conventional vacuum press equipment.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment, and FIGS. 2 to 5 are sectional views showing a conventional manufacturing method. In each figure, the same reference numerals indicate the same or corresponding parts. (1) is a press heating plate, (2) is a cushioning material, (3) is a patch plate, (4) is a copper foil, (5) is a prepreg, (7) is a film, and (10) is a vacuum hose.

Claims (2)

[Claims] (1) Laminated prepregs are sandwiched between multiple backing plates, covered with a film, and while the inside is kept in vacuum, the resin is cured by heating and pressurizing with a press. A method for manufacturing an FRP laminate. (2) The method for manufacturing an FRP laminate according to claim 1, characterized in that a layered prepreg is further laminated with copper foil.