JPS6359866B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding intermediate useful for making fiber-reinforced plastic tubular bodies, particularly curved pipes.

Fiber-reinforced plastic tubular bodies can be used not only in straight tubular bodies such as golf shafts and fishing rods, but also in tone arms of record players, bent arm shafts such as golf putter clubs, racket frames, badminton frames, and motorcycle handles. In addition, it is being used as tubular bodies with bent arms, such as pipe material for chairs.

These fiber-reinforced plastic tubular bodies are formed using a filament winding method, a tape wrapping method, a reinforcing fiber composition impregnated with a matrix resin is wrapped around a rubber elastic tubular body, and a mold is used to form the tubular body. Methods such as applying pressure from the inside and heat curing are being developed.

Both the filament winding method and the tape wrapping method use a molded core, which is an effective method for making a straight tubular body, but it is said that the core cannot be removed when making a tubular body with bent arms. It's inconvenient. Furthermore, during curing, external pressure such as tape contraction force or inert gas is often applied, which poses a problem in that the reinforcing fibers tend to meander. From this point of view, a molding method using a tubular body having rubber elasticity is an extremely effective molding method. However, this molding method using elastic rubber tubes also has weaknesses. In other words, the adhesiveness of the resin-impregnated reinforcing fiber tubular layer wrapped around the outer circumference of the elastic rubber tube may cause bending wrinkles, and during molding operations, it may stick to the inside of the mold, causing disturbances in fiber orientation. There was a problem with not being able to demonstrate sufficient strength. Therefore, in order to improve these disadvantages and at the same time omit the resin impregnation process, the present inventors developed a molding intermediate consisting of an elastic rubber tube/matrix resin layer/reinforcing fiber tubular layer arranged in this order from the inside. was developed. The reinforcing fiber tubular layer as the outermost layer of this molding intermediate is usually made of:
It is in a state where it is not impregnated with matrix resin. Furthermore, this reinforcing fiber tubular layer has conventionally been formed by laminating several braided tubular bodies, or by winding a plain weave or satin weave cloth fabric in a drainboard shape. However, the fiber compositions used for such reinforcing fiber tubular layers are all produced by stringing and weaving continuous fiber bundles,
Furthermore, a two-step processing step is required, in which these fiber compositions are coated on a rubber tube coated with a matrix resin to form a reinforcing fiber tubular layer.
This method has disadvantages in terms of the process of producing molded intermediates in large quantities and economically.

As a result of various studies, the present inventors omitted the steps of braiding and fabricating fabrics, and wound an unimpregnated fiber bundle on a matrix resin layer having a rubber layer as an inner layer using a filament winding method. The present inventors have arrived at the invention of a molding intermediate that directly forms a reinforcing fiber tubular layer.

That is, the feature of the present invention is that, as shown in FIGS. 1 and 2, the elastic rubber tube 1/
The molding intermediate is laminated in the order of matrix resin layer 2/reinforcing fiber tubular layer 3 formed by filament winding using unimpregnated fiber bundles.

What is the elastic rubber tube used in carrying out the present invention? When the molding intermediate of the present invention is mounted in a mold and molded by applying internal pressure, a pressurized fluid such as air or other inert gas is injected into the tube. Any material can be used as long as it expands when introduced and can provide enough pressure to impregnate the reinforcing fiber layer with the matrix resin, such as various rubber elastic materials such as natural rubber, acrylonitrile rubber, butyl rubber, etc. can be used.

Although various types of matrix resin layers can be used in carrying out the present invention, it is preferable that the matrix resin layer has low tackiness at room temperature.
Such a matrix resin layer may be a B-stage thermosetting resin tube, film, or sheet wrapped around it, and examples of the resin include epoxy resin, unsaturated polyester resin, polyamide resin, Examples include polycarbonate resin.

By making this matrix resin layer non-adhesive at room temperature, the work of forming the fiber reinforcing layer on the outer layer of the matrix resin can be carried out without any trouble caused by the adhesion of the matrix resin. This is more preferable because it allows

In addition, the molding intermediate produced by this method has no stickiness during molding, so there is no disturbance in fiber orientation due to bending wrinkles of the reinforcing fiber tubular body, and the properties of the reinforcing fibers are maintained sufficiently. A molded article can be obtained.

Various types of fibers such as glass fibers, aromatic polyamide fibers, carbon fibers, graphite fibers, silicon carbide fibers, and titanium fibers can be used as the reinforcing fibers used in carrying out the present invention.
Moreover, these fibers can be used alone or in combination with each other. When the reinforcing fiber tubular layer is formed using the filament winding method, the fiber bundles do not intersect with each other as in conventional braided or cross woven fabrics, so when internal pressure is applied during heat curing, the tubular layer swells and molds. It has the advantage of being easy to adhere to. However, since the fiber bundles do not intersect with each other and are not impregnated with resin, the fiber tubular body tends to collapse easily. Collapse can be prevented by increasing the number of pieces.

To make the molded intermediate of the present invention, a metal core is attached to an elastic rubber tube coated with matrix resin to maintain rigidity as shown in FIG. 3a, and as shown in FIG. 3b. , Tuck both ends of this core with the chuck part of the filament winding machine,
A fiber bundle that is not impregnated with resin is wound to a predetermined thickness and laminated structure. After winding, the metal core is removed to obtain a molding intermediate as shown in FIGS. 1 and 2.

Since the molding intermediate of the present invention has a structure as shown in FIGS. 1 and 2, it is easy to release the elastic rubber tube from the molded product after curing. Furthermore, since the reinforcing fibers are not impregnated with matrix resin, and the matrix resin can flow from the inner layer to the reinforcing fiber layer, it is extremely easy to form a smooth and glossy reinforcing fiber layer. be.

In order to make a molded product using the molding intermediate of the present invention, the molding intermediate having the structure shown in FIGS. 1 and 2 is mounted in a mold, the mold is tightened, and high pressure is By injecting a gas, applying pressure, and heating the mold, the flow of the matrix resin is started to promote the impregnation of the resin into the reinforcing fiber layer, and the resin layer is cured in one step. After forming a molded body with a hollow cross-sectional shape, the rubber tube may be extracted.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a molding intermediate of the present invention, and FIG. 2 is a sectional view thereof. Fig. 3a shows a matrix resin-coated elastic rubber tube equipped with a metal core, and Fig. 3b shows an elastic rubber tube on which an unimpregnated fiber bundle is wound by the filament winding method.
This shows how the reinforcing fiber tubular layer is made. DESCRIPTION OF SYMBOLS 1... Elastic rubber tube, 2... Matrix resin layer, 3... Reinforcing fiber layer, 4... Metal core, 5
...Reinforcing fibers coated with matrix resin layer, 6...Chuck portion, 7...Unimpregnated fiber bundle, 8
... Yarn feeding guide.

Claims (1)

[Claims] 1. Elastic rubber tube/matrix resin layer/
1. A molding intermediate comprising reinforcing fiber tubular layers formed by filament winding using unimpregnated fiber bundles and laminated in an arranged order. 2. The molding intermediate according to claim 1, wherein the matrix resin layer is made of a resin that is non-adhesive at room temperature.