JPS5829620A - Intermediate to be molded into tubular item - Google Patents

Abstract

PURPOSE:To obtain the titled intermediate useful for making a fiber reinforced plastic tubular item, in particular a bent pipe, by winding, round a pressure pipe, a composite sheet comprising specified reinforcing fibre sheet-like member and uncured matrix resin sheet-like member that are laminated. CONSTITUTION:A reinforcing fiber sheet-like member 1 (e.g. carbon fiber satin weave cross textile, etc.) having a thickness of 0.1-0.7mm. and a weight of 23g/ m<2>-550g/m<2> and the uncured matrix resin sheet 2 (for example, of an epoxy resin, an unsaturated polyester resin, etc.) having a thickness of 0.06-0.5mm. and a weight of 80g/m<2>-600g/m<2> are put together to obtain a laminate 3. Then after the laminate 3 is wound round a pressure pipe 4 (for example, a nylon resin, butyl rubber, etc.), into which a steel core 5 is inserted, with the resin sheet-like member 2 inside, and the steel core 5 is removed to obtain the intended intermediate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tubular body made of fiber-reinforced plastic, particularly an intermediate for forming a tubular body useful for making a curved pipe.

Fiber-reinforced plastic tubular bodies can be used not only in straight shapes such as golf club shafts and fishing rods, but also in the 1-in arm of record players, the bent arm of golf putter clubs, the bent arm of golf putter clubs, the racket fly, etc., as well as the pipes of chairs and bicycles. Its use as a tubular body with bent arms is being promoted.

Conventionally, these fiber-reinforced plastic tubular bodies have been formed using the filament winding method, tape wrapping method,
A method has been developed in which a reinforcing fiber composition impregnated with a matrix resin is wound around a pressurizing tube, which is then pressurized from inside the tubular body using a mold and cured by heating.

Both the filament winding method and the tape wrapping method use a molded core, so they are effective methods for making straight tubular bodies, but they have the disadvantage that the core cannot be removed when making curved pipes. From this point of view, a molding method using a pressure tube made of a rubber-like elastic tube or a plastic film tube is an extremely useful method.

However, the weak point of this molding method is that reinforcing fiber prepreg impregnated with matrix resin is wrapped around the outside of a pressure tube made of rubber elastic or plastic film tube, which is then bent into a curved tube shape and attached to the mold. case,
Because it is impossible to apply tension to the reinforcing fibers and attach them to the mold while bending them, bending wrinkles occur in the prepreg.
Due to the disordered fiber orientation, the strength utilization rate of the reinforcing fibers decreases, which is inconvenient for fiber-reinforced plastic curved pipes used in fields that require high strength such as golf shafts and racket frames. Furthermore, when used in the field of audio equipment, etc., it causes disadvantages such as distortion in sound propagation.

The disadvantage of the conventional internal pressure molding method is that it uses a reinforcing fiber sheet impregnated with resin, which can stick to the pressure tube, or can stick to the inner wall surface when installed in a preheated mold. [7] Disturbance of fiber orientation is likely to occur, which is a factor in reducing the strength of the molded article. Furthermore, the tackiness of this resin also caused disadvantages such as the molding material becoming sticky during molding operations.

Therefore, the inventors of the present invention conducted research with the aim of producing an intermediate for forming tubular objects free of such defects, and completed the present invention.

The tubular product forming intermediate of the present invention is shown in Figure 1(a).
It has a structure as shown in the perspective view, and its cross-sectional structure is as shown in Figure 1(b), in which an uncured matrix resin film or sheet is superimposed on one side of a sheet-like woven or knitted fabric. This is an intermediate body for forming a tubular article, which is wound around a pressurizing tube made of a tubular body having rubber elasticity or a plastic film tube.

The pressurizing tube used in carrying out the present invention refers to a pressurizing pipe that is used to supply pressurized fluid such as air or other inert gas when the molding intermediate of the present invention is mounted in a mold and molded by applying internal pressure. When introduced, it expands and can apply pressure to sufficiently impregnate the reinforcing fiber layer with the matrix resin, and also has good mold releasability from the matrix resin, such as Evanylon resin, polypropylene resin, polyester. A film tube made of plastic such as resin or a tubular body made of natural or artificial rubber can be used.

Although various types of uncured matrix resin sheet materials can be used in carrying out the present invention, it is preferable to use materials that are less sticky at room temperature. Such a matrix resin is a thermosetting resin in a B-stage state, and examples thereof include epoxy resins, polyester resins, polyamide resins, and the like.

Further, as the reinforcing fibers used in the present invention, various types of fibers such as glass mitten fibers, carbon fibers, graphite fibers, silicon carbide fibers, and aromatic polyamide fibers can be used, and these fibers can be used in fabrics, braids, etc. can be used.

The intermediate body for forming a tubular article of the present invention will be explained based on an example of an intermediate body for forming a racket frame.

As shown in Figure 2(a), the Toshiori cross fabric (1) using carbon fiber (weighing: 400 r/rinse 2, length = 1.
An uncured matrix resin sheet (fabric weight:
200 y/m2) (2) to 1 (knitting, textile/
A sheet body (3) made of the product IQJ of resin sheets is made. On top of this sheet body is a steel core (5 mm) with an outer diameter of 3.0ψ
) with an outer diameter of ZOφ and an inner diameter of 507 mm.
4), making sure that the rubber tubes do not protrude slightly from both ends of the sheet body (see Figure 2 (b)), then Figure 2 (c).
, As shown in (d), the sheet body is spirally wound around the pressure tube. Since the resin sheet-like material is always wound so that it becomes the inner layer, the outermost layer is composed of a non-resin-impregnated fabric layer, which can prevent the adhesiveness of the resin. After winding, the steel core can be removed to obtain the tubular product forming intermediate of the present invention. The weight of the molded body is about 200~
The larger the basis weight of the resin sheet or fiber sheet used to keep the fiber volume content (v) of the molded body within the range of s o o tr and 40 to 60 vol %, the greater the wall thickness. Thick (and has the advantage of reducing the number of wrappings.Currently available fiber sheets can have various weights, but take into consideration the amount of resin attached, disordered fiber orientation, weaving density, wall thickness, etc.) Then, the size of the fiber sheet that can be used as a molding intermediate is approximately 26 to 550.
f/rn2. In addition, various types of attachment of the uncured matrix resin sheet may be considered, but in order to obtain the desired effect, 1. In relation to fIl and the basis weight of the fiber-like material, it is preferably in the range of 80 to 600 fr/m2, and below this, it is possible to use several sheets of fiber-like material by laminating them in order to increase the thickness. This will cause problems in workability.On the other hand, if the resin (It) is too thick, the molded product's vl, elastic modulus, and strength will decrease.

To make a molded object using the intermediate for forming a tubular object of the present invention, pressurizing tubes at both ends of the intermediate are set in a large pouring jig,
This is poured into a preheated mold. After clamping the mold, N and gas 8Kf10n2 are injected into the pressurizing tube. As a result, when the reinforcing fiber sheet material is impregnated with the low-viscosity 7-link resin, the resin-impregnated fiber sheet material is pressed onto the inner wall surface of the mold having a predetermined shape. , harden.

After curing, by removing +1y of the rubber tube, a racket frame blank tube with a hollow irregular cross-sectional shape can be obtained.

[Brief explanation of drawings]

Figure 1, 0) shows a perspective view of an intermediate for forming a tubular object. FIG. 1, (b) shows a sectional view taken along the line AA' of the intermediate for forming a tubular object. Figure 2(a) shows a sheet body in which a matrix resin sheet material is superimposed on a reinforcing fiber sheet material. Figure-
2(b) shows a state in which the pressurizing tube with the core inserted therein is placed on the sheet body. Figures 2(C) and 2(d) show the state in which the sheet body is rolled up onto this pressure tube. 1. Reinforcing fiber sheet material 2. Matrix resin sheet material 5 Core body

Claims (1)

[Claims] Thickness 0.1-0.7 mm, mesh 'Fl' 23 g/l
n" ~ 55 (1y/m2 reinforcing fiber sheet material and thickness 0.06 ~ 0.5 tan, basis weight a o y/-'
~6F] An intermediate product for forming a tubular object, in which a composite sheet body, in which a non-quaternized matrix resin sheet material of Of/-2 is superimposed, is wound around a pressurizing tube in a small number (two or more plies).