JPS6153952B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of molding a composite material board in which a reinforcing fiber cloth such as glass fiber is impregnated with a resin such as polyethylene.

Conventionally, this type of molding method, as seen in Japanese Patent Publication No. 47-27796, involves heating sheet-like reinforcing fibers coated with resin and then laminating them one after another, and then pressing the laminate with a compression roll. A method is provided in which the material is compression molded and then cooled using a cooling roll.

According to this conventional method, pressure is only applied to the laminate while it is being applied to the compression roll, and after passing through the compression roll, it expands. Therefore, the amount of resin attached increases according to the amount of expansion, and the content of reinforcing fibers is approximately 40%V.
(volume %) is the limit. In other words, the amount of expensive resin used increases. Moreover, there is a possibility that bubbles will be generated again in the laminate during expansion.

An object of the present invention is to provide a method for molding a composite material plate that can greatly increase the fiber content and reduce the amount of resin used, and can also be molded while maintaining a sufficiently defoamed state. be.

In order to achieve the above object, the method for forming a composite material board of the present invention involves laminating a reinforcing fiber cloth, a thermoplastic resin sheet, and a thin metal plate coated with a release agent on both sides with the thermoplastic resin sheet in between. After connecting the inner end of the thin metal plate of this laminate to the mandrel, the laminate is wound around the mandrel while applying tension, and the outer end of the thin metal plate and the mandrel are connected with each other under tension. During this process, a high frequency voltage is applied, and the thermoplastic resin sheet is melted by dielectric heating to impregnate the reinforcing fiber cloth, and then cooled.

An embodiment of the present invention will be described below based on the drawings.

In Figure 1, 1 is a reinforced fiber cloth such as glass fiber, polyester fiber, or carbon fiber, 2 is a thermoplastic resin sheet made from polyethylene resin, nylon resin, polypropylene resin, etc., and 3 is a sheet with a mold release agent applied on both sides. These 1,
2 and 3 are formed into a laminate 5 through a plurality of guide rollers 4 with the thermoplastic resin sheet 2 as an intermediate, and then wound around a mandrel 6. The winding is carried out in such a way that the reinforcing fiber cloth 1 is on the outside, the thermoplastic resin sheet 2 is in the middle, and the thin metal plate is on the inside. It's being hung. Further, the metal thin plates 3 are heated by a heating device 8 before lamination. During winding, the inner end 5a of the laminate 5 is inserted into the groove 9 of the mandrel 6, as shown in FIG. 2, so that the inner end of the thin metal plate 3 is connected to the mandrel 6. Second
After the winding shown in the figure, a high frequency voltage is applied from a high frequency power source 11 between the outer end of the thin metal plate 3 and the core metal 6 with a tension force 10 acting on the outer end 5b of the laminate 5. As a result, the thermoplastic resin sheet 2 is melted by dielectric heating, and the reinforcing fiber cloth 1 is impregnated with the melted resin liquid. The gaps that tend to occur due to this impregnation are absorbed by wrapping using tension force. After sufficient dissolution and impregnation, it is then cooled. By peeling off the metal thin plate 3 in a slightly cooled state, a spiral-shaped composite material plate can be obtained. To use this composite material plate for a secondary purpose, it can be heated again to soften it and processed in the next step.

Note that before lamination, chopped stride may be supplied to the reinforcing fibers 1 and laminated, or pellet resin may be supplied to the thermoplastic resin sheet 2 and laminated.

As described above, according to the present invention, by melting the thermoplastic resin sheet by dielectric heating while applying tension to the laminate wound around the core metal, the melted resin liquid is applied to the reinforcing fiber cloth. A composite material plate can be easily obtained by impregnating the metal, followed by cooling and peeling off the metal sheet. In this way, impregnation and cooling are performed while applying tension and maintaining compression pressure, so no expansion occurs, the amount of resin used can be extremely reduced, and the content of reinforcing fibers can be greatly increased (approximately 60% %V) and can be molded while maintaining a sufficiently defoamed state.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic side view when laminating layers, and FIG. 2 is a side view when dissolving and impregnating layers. 1... Reinforced fiber cloth, 2... Thermoplastic resin sheet, 3... Metal thin plate, 4... Guide roller, 5...
Laminated body, 5a...inner end, 5b...outer end, 6...mandrel, 7...tension roller device, 8...heating device, 9...groove, 10...tension force, 11...
High frequency power supply.

Claims (1)

[Claims] 1. After laminating a reinforcing fiber cloth, a thermoplastic resin sheet, and a thin metal plate coated with a release agent on both sides with the thermoplastic resin sheet in the middle, and connecting the inner end of the metal thin plate of this laminate to the core metal, This laminate is wound around a core metal under tension, and with tension applied, a high frequency voltage is applied between the outer edge of the thin metal plate and the core metal, and the thermoplastic resin sheet is melted by dielectric heating. 1. A method for forming a composite material board, which comprises impregnating a reinforcing fiber cloth with the resin and cooling it.