JPH09267401A - Frp pipe and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the workability in a manufacturing process and to achieve higher physical properties by forming an FRP pipe by winding up flat yarn consisting of reinforcing fiber multifilament yarns having specific yarn width and a yarn width/yarn thickness ratio of a specific value or more. SOLUTION: Flat yarn 3 consisting of reinforcing fiber multifilament yarns is helically wound around the flexible tube core material 2 applied to a mandrel 1 at an angle of ±30 deg. with respect to the axial direction of the mandrel by a filament winding method (winding layer 4). Next, a helical winding layer 5 is provided at a winding angle of ±10 deg. and a helical winding layer 6 is further provided at a winding angle of 30 deg. to form a preform 7 consisting of a plurality of fat yarn winding layers. This flat yarn has yarn width of 4-30mm and a yarn width/yarn thickness ratio of 10 or more. When yarn width is below 4mm, flattening effect is reduced and, when yarn width exceeds 30mm, handling is difficult and, when the yarn width/yarn thickness ratio is below 10, it is difficult to suppress crimps small. Yarn width is about 4-16mm from an aspect of easiness to handle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FRP tube suitable for application to a tube having a complicated shape such as a bent tube such as a racket frame and a method for manufacturing the same.

[0002]

2. Description of the Related Art FRP tubes are used for various purposes such as sports and leisure because of their light weight and high strength. Usually, the FRP pipe is made by winding a reinforcing fiber thread impregnated with resin on a core material and curing it directly, or
It is molded by once forming a preform, setting the preform in a mold and curing the resin. The latter method is often used for a pipe having a relatively complicated shape such as a bent pipe.

By the way, the present applicant has previously proposed a woven fabric using a flat yarn made of a reinforced multifilament yarn as a reinforced fiber woven fabric used for molding an FRP product (Japanese Patent Laid-Open No. 6-136632). ). As a result, a reinforced fabric having less bending, being thin, having a low basis weight and having high physical properties was realized.

[0004]

DISCLOSURE OF THE INVENTION The present invention newly aims to develop a reinforcing fiber flat yarn into an FRP pipe, which has good workability in the manufacturing process and can achieve higher physical properties. An object of the present invention is to provide an FRP tube and a method for manufacturing the same.

[0005]

In order to solve the above problems, the FRP pipe of the present invention has a yarn width in a range of 4 to 30 mm and a yarn width / yarn thickness ratio of 10 or more. It is characterized by having a reinforcing fiber layer formed by winding up a flat yarn made of yarn.

This FRP pipe is suitable for application to a curved pipe, particularly a curved pipe having a relatively complicated shape such as a racket frame.

The FRP pipe forming preform according to the present invention has a yarn width in the range of 4 to 30 mm and a flat yarn made of reinforcing fiber multifilament yarn having a yarn width / yarn thickness ratio of 10 or more is rolled up. It is characterized by being formed by.

This preform is formed by winding up the flat yarn by a filament winding method.

When performing filament winding, a flat yarn impregnated with a resin may be wound, or a dry flat yarn not impregnated with a resin may be wound to form a dry preform.

The FRP pipe manufacturing method according to the present invention comprises a method of setting the preform formed as described above in a predetermined mold and molding the FRP pipe by heating and pressurizing. For example, it is possible to form the preform on a flexible tube, set it in a mold together with the flexible tube, and apply internal pressure to the flexible tube to perform heat molding.

When the preform is formed of the flat yarn impregnated with the resin, the resin may be cured by the internal pressure molding, and when the preform is formed of the dry flat yarn, the preform is formed. After setting in the mold,
A desired FR is obtained by a method of injecting a resin into the cavity of the mold, for example, a resin transfer molding method.
P-tubes can be molded.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a flat yarn made of reinforcing fiber multifilament yarn is required to have substantially no twist. Here, "substantially no twist" means a state in which there is no twist of 1 turn or more per 1 m of the yarn length. In other words, it means a realistic untwisted state.

When the flat yarn is twisted, the yarn width is narrowed and converged and thickened at the twisted portion, and unevenness is generated on the surface of the preform formed by the filament winding method. For this reason, when the FRP pipe is molded, stress is concentrated on the twisted portion when an external force acts, and the strength characteristics become non-uniform.

A preform formed by winding up a flat yarn having substantially no twist in the optimum flat state as described above is a filament winding method even if the fineness of the flat yarn is increased or the fiber density is increased. The crimps at the intersecting portions of the flat yarns when wound by are suppressed to be extremely small, and high strength characteristics can be obtained when they are made into FRP or CFRP. Further, since the fineness of the flat yarn can be increased, the flat yarn, and thus the preform, and further the FRP pipe can be manufactured at a lower cost.

Since the yarn is a flat yarn, the winding pitch can be increased even with the same basis weight during filament winding, and the number of times of winding can be reduced by that amount to efficiently form a preform. Further, as described above, the crimp can be suppressed to be extremely small when the preform is formed by the filament winding method, so that the fiber areal weight can be set high. Therefore, when molded into an FRP pipe, the fiber content can be set high and the resin-rich portion can be suppressed to an extremely small value, so that an FRP pipe having high strength and uniform strength characteristics can be obtained.

Further, since the reinforcing fiber multifilament yarn maintained in a flat state is used, the impregnation property of the resin is extremely good. Therefore, a composite material having more uniform properties can be obtained, and target strength properties can be easily obtained.

The flat yarn has a yarn width in the range of 4 to 30 mm and a yarn width / yarn thickness of 10 or more. Thread width is 4mm
If it is less than 30 m, the effect of flattening as described above is small, and it is 30 m.
If it exceeds m, handling becomes difficult. When the yarn width / thread thickness ratio is less than 10, it is difficult to suppress the above-described crimp to a small level. The thread width is 4 to 16 mm
Is easy to handle.

As a method for producing the flat yarn itself as described above, for example, in a manufacturing process of a reinforcing fiber yarn, a fiber bundle composed of a plurality of reinforcing fibers is spread to a predetermined width by a roll or the like,
The flat shape may be held as it is, or the shape may be held by a sizing agent or the like so as not to return to the original shape. In particular, in order to maintain a good flat shape, it is advisable to attach a small amount of a sizing agent of less than 2% by weight to the flat yarn.

Using the flat yarn made of the reinforcing fiber multifilament yarn as described above, a preform is formed, for example, as shown in FIG. 1, and the preform is used, for example, as shown in FIG. F as a curved pipe
The RP racket frame is molded.

In FIG. 1, first, as shown in FIG. 1 (A), on a flexible tube core material 2 covered with a mandrel 1,
The flat yarn 3 made of reinforcing fiber multifilament yarn is helically wound by the filament winding method. In the present embodiment, the helical winding layer 4 has a winding angle of ± 30 ° with respect to the axial direction of the preform (axial direction of the mandrel 1 or the core material 2).

Next, as shown in FIG. 1B, the winding angle ± 1
The flat yarn 3 is helically wound at 0 ° by the filament winding method. As shown in FIG. 1C, the flat yarn 3 having a winding angle of ± 30 ° is provided on the helical winding layer 5.
A helical winding layer 6 is provided by winding up. In this way, the preform 7 including a plurality of flat yarn winding layers is formed.

Using the preform 7 formed as described above, an FRP racket frame is molded as shown in FIG. 2, for example.

The preform 7 shown in FIG. 1 is shaped like a racket frame like the preform 11 in FIG. 2, and the preform 11 is set in the cavity of the molding die 12.

Next, the resin composition in which the main agent 13 and the curing agent 14 are mixed at a predetermined ratio is put into a mold. The mold 12 is heated, and the inside of the preform tube 2 is pressurized to cure the resin, thereby obtaining a FRP racket frame.

In the above example, the molding method of the FRP racket frame by the so-called resin transfer molding method is shown, but it may be molded by other methods. For example, in forming the preform, a flat yarn made of reinforcing fiber multifilament yarn impregnated with a matrix resin in advance is used, and the preform is formed by winding it by the winding method as shown in FIG. The resin may be cured by setting the reform in a racket shape and then setting it in a mold.

Further, the kind of the reinforcing fiber in the present invention is not particularly limited and, for example, glass fiber, carbon fiber, and organic high elastic modulus fiber such as polyaramid fiber can be used.

The type of matrix resin is also not particularly limited, and any of thermosetting resins, thermoplastic resins, and mixed resins thereof can be used. Generally, FRP
Thermosetting resins are most often used for products, and epoxy resins are most widely used.

Examples of the epoxy resin include bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin,
Urethane-modified epoxy resin, brominated bisphenol A
Various epoxy resins such as type epoxy resin can be used. These epoxy resins can be used alone or in combination of two or more kinds, and can be used in liquid form to solid form. Usually, a one-component curing type epoxy resin to which a curing agent is added is often used. The curing agent is not particularly limited, but a latent type curing agent is preferable in terms of storability. As an example of the latent curing agent, a guanidine-based curing agent such as dicyandiamide is preferably used.

In the FRP racket frame configured as described above, since the specific reinforcing fiber flat yarn is used as described above, the high fiber basis weight can be obtained and the reinforcing fiber wound by the filament winding method can be used. The unevenness (crimp) of the layers is extremely small, and a racket frame having uniform and high physical properties can be realized. Also, the workability in the preform formation process is extremely good.

[0030]

【Example】

Example 1 First, Toray Industries, Inc. carbon fiber "Torayca" T700SC-
12K (single yarn diameter 7μ, number of filaments 12,000,
Fineness of 800 tex, density of 1.8 g / cm ³ ) and thread width of 5
mm, the yarn thickness is 0.1 mm, and the sizing agent is attached in an amount of 1% by weight so that the yarn width / the yarn thickness ratio becomes 50 to maintain the flat shape. Next, on the core material with an outer diameter of 15 mm, bend diameter 2
While covering with a nylon tube of 4 mm and a thickness of 70 μ, the above-mentioned carbon fiber flat yarn drawn from the creel (creel tension of 400 g) was passed over the eye guide to control the yarn width to be constant (± 30 ° / ± 10 ° /
A dry preform was produced by winding three layers around (± 30 °) structure, and the dry preform was decoreed by hand together with the tube. The core removal was very easy, and no yarn disorder was required.

The dry preform was placed in a mold and resin was injected / cured while pressurizing the inside of the tube to obtain a hollow bent tube. The bending rigidity of this bent pipe is 2.16.
It was × 10 ⁸ Pa (2.2 × 10 ⁸ kgf / mm ² ).

Comparative Example 1 The same operation as in Example 1 was carried out except that the same carbon fiber as in Example 1 was not fixed in a flat state. The cross-sectional shape of the reinforcing fiber yarn wound around the core material has a width of about 1 m.
It was a rounded (thick) elliptical shape of m (yarn thickness was 0.5 mm, yarn width / thread thickness ratio was 2). Although a considerable amount of force was required for decoreing, although it was possible to decore it by hand, the yarn disorder was remarkable. This is because the width of the wound reinforcing fiber yarn is small, and the flat yarn of Example 1 tends to be wound tightly as a surface pressure, whereas it tends to be tightly wound around a core material as a linear pressure. Further, the bending rigidity of the hollow bent pipe obtained by the resin transfer molding is 1.96 × 10 ⁸ Pa (2.0 × 10
^{It was 8} kgf / mm ² ). This is because the bending of the yarn at the point where the yarns intersect has an effect.

[0033]

As described above, according to the present invention,
Form a preform using specific reinforcing fiber flat yarn,
By molding an FRP tube using the preform, an FRP tube having higher physical properties can be realized. Further, the workability of forming a preform by the filament winding method can be improved.

[Brief description of drawings]

FIG. 1 is a side view showing a method for forming a preform according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a method of molding an FRP racket frame using the preform of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mandrel 2 Flexible tube core material 3 Reinforcing fibers 4, 5, 6 Reinforcing fiber Helical winding layer of flat yarn 7 Preform 11 Preformed mold 12 Mold 13 Main agent (matrix resin) 14 Hardener

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Claims (9)

[Claims] 1. A reinforcing fiber layer formed by winding up a flat yarn composed of a reinforcing fiber multifilament yarn having a yarn width in a range of 4 to 30 mm and a yarn width / thread thickness ratio of 10 or more. FRP tube to do. 2. The FRP of claim 1, comprising a bent tube.
tube. 3. The F of claim 2 which is a racket frame.
RP tube. 4. A FRP pipe molding characterized by being formed by winding up a flat yarn made of a reinforcing fiber multifilament yarn having a yarn width in a range of 4 to 30 mm and a yarn width / thread thickness ratio of 10 or more. preform. 5. The FR, wherein the FRP pipe molding preform according to claim 4 is formed by a filament winding method.
Manufacturing method of preform for P pipe molding. 6. The method for producing a preform for FRP pipe molding according to claim 5, wherein a flat yarn impregnated with a resin is wound up. 7. The method for producing a preform for FRP pipe molding according to claim 5, wherein a dry flat yarn not impregnated with a resin is wound up. 8. An FRP pipe is formed by setting the FRP pipe forming preform manufactured by the method according to any one of claims 5 to 7 in a mold.
FRP pipe manufacturing method. 9. The method for manufacturing an FRP pipe according to claim 8, wherein the FRP pipe is a bent pipe.