JP2002371139A - Reinforcing fiber composition for frp, and frp molded article produced by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcing fiber composition easy to handle, giving an lightweight FRP method article produced at a low cost and enabling the molding of the article having a complicate three-dimensional form. SOLUTION: High strength fibers 2 are aligned to form a fiber bundle 3 covered with a cylindrical sleeve 4 on the circumference of the bundle 3. The sleeve 4 is formed by knitting a braid yarn 5. The reinforcing fiber composition 1 is arranged along the direction of stress applied to a molded article and a thermosetting resin impregnated in the reinforcing composition 1 is cured to obtain the FRP molded article.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber reinforcing material used for a fiber-reinforced resin (so-called FRP) molded article and an FRP molded article using the same. The present invention relates to a fiber reinforced material for FRP and an FRP molded article using the same, which can easily cope with a molded article having a complicated and three-dimensional shape, and can easily reduce the weight of the molded article and is easy to handle.

[0002]

2. Description of the Related Art In order to enhance durability and power generation efficiency, wind turbine blades used for wind power generation are required to have not only a predetermined outer surface shape but also high strength and light weight capable of withstanding large centrifugal force and rotational force. . For this reason, FRP molded bodies reinforced with high-strength fibers such as glass fibers are often used for the main girders.

Hitherto, a roving cloth woven from glass roving or the like which effectively exhibits high strength has been used as a fiber reinforcing material used for an FRP molded body such as a main girder of a wind turbine blade. That is, the main girder of the blade for a windmill is formed in a flat and thin shape at the tip end side, and after forming this half portion by FRP, it is integrated with the other half portions. The molded body is formed by, for example, bringing a roving cloth impregnated with a curable resin into close contact with an inner surface of a mold having a predetermined shape by vacuum and / or injection, and curing the curable resin.

[0004]

Since the above-mentioned roving cloth is woven into a sheet of a fixed width such as a plain weave, it has the following problems. Since the portion protruding from the mold is cut and lost when it is made to conform to the above-mentioned mold, the manufacturing cost of the molded body is high. Since it is woven in a sheet shape, it is difficult to conform to a three-dimensional curved surface excluding a cylindrical surface, and it is not easy to cope with a molded article having a complicated shape such as a spiral shape or a shape having many curved surfaces. It is necessary to arrange a large amount of fiber reinforcing material in the area where stress is applied to the molded body, but since the roving cloth is in the form of a thin sheet, it is necessary to laminate a large number of pieces cut in a predetermined shape, The arrangement work is complicated, and the cut loss increases. The roving cloth is woven to a predetermined width and wound on a core material, and it is necessary to cut out a predetermined shape in a state where the roving cloth is drawn out and spread in a sheet shape.
In particular, when used for a large-sized molded product, a large working space is required for the above cutting.

The present invention solves the above-mentioned problems, can form an FRP molded article at low cost, can easily handle a complicated and three-dimensionally shaped molded article, and can easily reduce the weight of the molded article and handle it. It is an object of the present invention to provide a fiber reinforcing material for FRP which is easy and an FRP molded body using the same.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention will be described with reference to FIGS. 1 to 6 showing an embodiment of the present invention. That is, the invention of claim 1 relates to a fiber reinforcing material for FRP, and a fiber bundle portion formed by aligning high-strength fibers (2).
(3), and a tubular sleeve portion (4) disposed around the fiber bundle portion (3).
It is characterized by being formed by braiding in (5).

A tenth aspect of the present invention relates to an FRP molded article, wherein the fiber reinforcing material for FRP (1) is replaced with a molded article (7).
This fiber reinforcement is placed along the direction of the stress
It is characterized in that the curable resin impregnated in (1) is cured and molded.

[0008]

The above-mentioned fiber reinforced material for FRP has a tubular sleeve portion braided around a fiber bundle portion in which high-strength fibers are aligned, and is formed in a string shape having a substantially perfect cross section. It is wound on a take-up reel. The string-shaped fiber reinforcing material is used for an FRP molded body by a molding method similar to a conventional roving cloth, such as hand lay-up, RTM, vacuum, or a combination thereof.

That is, the procedure of disposing the fiber reinforcing material in the molding die is as follows: first, the fiber is cut into a length suitable for the location where the reinforcing material is to be placed in the molding die; Be placed. Further, at a place where high stress is applied, such as a part of the molded body that bears bending, the above-mentioned fiber reinforcing material is cut to a required length and arranged intensively. At this time,
Since the fiber reinforcing material has a string shape, even if the mold has a complicated curved surface, the fiber is freely bent and follows the surface of the mold. Since the fiber bundle is bundled by a braided sleeve, each high-strength fiber does not come apart or become entangled. In addition, the high-strength fiber is easily displaced when subjected to a stress in the diametric direction, and the cross-sectional shape of the fiber bundle is deformed into an elliptical shape, a rectangular shape, a flat shape, a U-shape or the like. For this reason, the fiber reinforcing material is easily adapted to the surface shape of the mold by pressing against the mold or vacuuming by vacuum molding.

[0010] The fiber reinforcing material placed in the above-mentioned molding die is impregnated with a curable resin in advance similarly to the conventional FRP molding, or is impregnated with the curable resin after the above-mentioned arrangement.
By curing this curable resin, a desired FRP molded body is formed.

[0011] The high-strength fibers forming the fiber bundle portion include:
A fiber material having high tensile strength, compressive strength, and elastic modulus is used. Specifically, one or more fibers selected from glass fibers, carbon fibers, and aramid fibers are preferable. The high-strength fibers need only be aligned substantially in parallel, and preferably have no twist or are slightly twisted. In addition,
The thickness of the fiber bundle portion is set according to the application. For example, a large molded body such as a main girder of a windmill blade has a diameter of 10 to 30 mm. It is suitable because it can be arranged well. This fiber bundle part
Normally, the cross section is formed in a substantially perfect circular shape at the time of manufacturing, but any shape may be used as long as it easily deforms when subjected to a stress in the diametric direction. Specifically, in the case of the above-mentioned thickness, for example, 6 to 8 mm What can be made into a flat plate of a degree is preferable.

In the above-mentioned fiber bundle portion, it is preferable that an inter-fiber member be disposed between high-strength fibers, since the inter-fiber member forms an infiltration path for the curable resin, so that the impregnation of the resin is improved. In addition, since the inter-fiber member is disposed between the high-strength fibers, the high-strength fibers can be easily moved in the diameter direction, and the fiber reinforcing material is easily bent and the cross-sectional shape is easily deformed. In the case where the inter-fiber member has a cushioning property, a restoring force to a perfect circle is generated in the fiber reinforcing material, so that the resin impregnating property is further improved. It will be good.

The inter-fiber member includes cotton yarn, non-twist yarn, C
Natural fibers, synthetic fibers, and inorganic fibers such as SM, hemp yarn, urethane yarn, and vinylon yarn can be used. These are preferably made of a material which is easily impregnated with the curable resin, such as a fluffy material, but may be a material which is joined to the curable resin by an anchor effect. Further, the inter-fiber member may be any material as long as the impregnating property of the curable resin and the mobility of the high-strength fiber are improved, and instead of the fiber material, glass beads, a glass balloon, or a powder material made of another inorganic filler material Can be used.
Further, the granular material and the fiber material may be used in combination.

When the above-mentioned inter-fiber member is used, the high-strength fiber in the fiber bundle is preferably at least 50% by weight, more preferably at least 70% by weight.

[0015] The braid density of the sleeve portion is such that the high-strength fibers of the fiber bundle portion are bundled, and the high-strength fibers are displaced in the diametrical direction so that the cross-sectional shape of the fiber bundle portion can be deformed. For example, the diameter of the fiber bundle part is 10
When it is 30 mm, it is formed by braiding 16 to 64 braided yarns.

The braid constituting the above-mentioned sleeve portion is not limited to a specific material, but it is preferable that wrinkles and slack do not easily occur even when a fiber-reinforced material is disposed in the sharply curved portion. In addition, it is preferable to use high-strength fibers for the braiding yarn in order to enhance the reinforcing effect of the fiber reinforcing material. From the viewpoint of impregnation, chemical bonding between the fiber reinforcing materials, and the like, the fiber bundle portion is formed. It is more preferable to use the same kind of high-strength fiber as the high-strength fiber.

It is to be noted that the FRP molded article molded using the above-mentioned fiber reinforcing material is an FRP molded article to which a stress is applied in a predetermined direction so that the characteristics of the above fiber reinforcing material can be effectively exhibited. Often suitable for large structures, such as, but not limited to, wind turbine blades, bridges, large dome panels, etc.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of a fiber reinforcing material for FRP of the present invention, FIG. 1 is a partially cutaway perspective view of the fiber reinforcing material, FIG. 2 is an enlarged sectional view of a fiber bundle portion, and FIG. It is sectional drawing which shows the general | schematic shape of a reinforcement material.

As shown in FIG. 1, this fiber reinforcing material (1)
Consists of a fiber bundle portion (3) formed by aligning glass rovings (2), which are high-strength fibers, and a cylindrical sleeve portion (4) disposed around the fiber bundle portion (3). The sleeve portion (4) is formed by braiding with a braided yarn (5) made of long glass fiber.

The glass roving (2) can be made of any material as long as it can be made into a long fiber.
Glass, S glass, AR glass and the like can be mentioned. The glass roving (2) is coated with a binder having compatibility and reactivity with a curable resin such as an epoxy resin, an unsaturated polyester resin, and a diallyl phthalate resin, respectively. 57 for 9 μm diameter
5 tex to nominal diameter 23 μm and 4400 tex are used. In addition, in order to reduce the working space at the time of braiding described later, about 3 to 10 of these glass rovings may be aligned to form a cheese shape. Although glass roving is used as the high-strength fiber in this embodiment, carbon fiber or aramid fiber can be used as the high-strength fiber of the present invention.

As shown in FIG. 2, an inter-fiber member (6) made of a fiber material such as cotton thread is randomly arranged between the glass rovings (2) in the fiber bundle (3). .
By the arrangement of the inter-fiber member (6), the glass roving (2) is set so as to occupy about 70% by weight of the entire fiber bundle (3). The inter-fiber member (6) may be arranged regularly between the glass rovings (2 ...). In this embodiment, a fiber material is used for the inter-fiber member (6). However, in the present invention, a powdery or granular material made of an inorganic filler such as glass beads may be used for the inter-fiber member.

The braided yarn (5) constituting the sleeve part (4)
ECG75 shown in, for example, JIS R3412
1/0, ECG75 1/2, ECG37 1/0, E
A glass thread such as CG371 / 2 is used, and the same kind of binder as the above-mentioned glass roving is applied.

The fiber reinforcing material (1) is braided by using a generally used braiding machine (braiding machine). That is, the glass roving (2) and the inter-fiber member (6) are pulled out from a creel or the like in which a required number of them are arranged, and are formed into a rope shape to form a fiber bundle portion (3) having an outer diameter of, for example, about 10 to 30 mm. . The rope-shaped fiber bundle (3) is guided to a braiding machine, and the above-mentioned braided yarn (5) is wrapped around 16-
The sleeve part (4) is formed using 64 pieces. After the fiber bundle (3) is bundled by the sleeve (4), the fiber reinforcing material (1) formed into a string is wound on a take-up reel or the like.

The above-mentioned sleeve part (4) is made of a fiber reinforcing material.
When the (1) is pressed in the diameter direction, the glass roving (2) is easily displaced and the fiber bundle (3) is braided with such a gentleness that the sectional shape thereof is easily deformed. For this reason, at the time of braiding, the cross section is substantially a perfect circle as shown in FIG. 3A, but when a stress is applied in the diametrical direction, the elliptical shape shown in FIG. 3B or the elliptical shape shown in FIG. It becomes a rectangular shape and a flat plate shape as shown in FIG.
The U-shaped cross section shown in FIG.

Next, the formation of the main girder of the wind turbine blade using the above-mentioned fiber reinforced material for FRP will be described. FIG. 4 shows a half part of a main girder of the wind turbine blade.
4A is a perspective view in which a part of a half part is omitted, and FIG. 4B is a cross-sectional view in which a main part of the half part is enlarged.

As shown in FIG. 4A, the main girder (7)
Is formed in a semi-cylindrical shape with a thicker base end (8),
(9) The shape is such that the diameter increases slightly toward the side and then tapers and becomes flat. The fiber reinforcing material (1) is fed out of a take-up reel, cut to a required length, and cut along a forming die having an outer shape of a half part, in a length direction of the main girder (7). It is arranged in. At this time, the fiber reinforcing material (1) may be lightly pressed to be adapted to the molding die.

Since a larger stress is applied to the wind turbine blade at the base end (8) side than at the tip end (9) side, the fiber reinforcing material (1) is provided at the base end (8). The number is arranged more on the side, and the number of arrangements is reduced toward the tip (9). That is, as shown in FIG. 4 (b), the number of arrangements in each part is adjusted by shortening some of the fiber reinforcements (1).
Further, the fiber reinforcing material (1) is superposed in a plurality of layers in a portion where the number of arrangements is large, and is expanded in a lateral direction by the above-mentioned pressing or the like in a portion where the number is small.

Next, the above-mentioned fiber reinforcing material (1) is impregnated with a curable resin (10), and then vacuumed from the mold side. As a result, the fiber reinforcing material (1) impregnated with the curable resin (10) is pressed to the atmospheric pressure and adheres to the surface of the molding die, and excess curable resin (10) is eliminated. . The above-mentioned curable resin (10) may be impregnated in advance into the fiber reinforcing material (1) before being placed in the mold.

Due to the above-mentioned pressing, vacuum and / or injection, a pressing force is applied to each fiber reinforcing material (1) in the diametrical direction, and the cross-sectional shape is deformed. That is, FIG.
As shown in FIG. 5, a fiber reinforcing material (1) having a circular cross section and arranged in a predetermined length direction has a substantially square shape shown in FIG. 5B, an elliptical shape shown in FIG. A state is apparently arranged with no gap, such as a flat plate shape shown in (d). Further, as shown in FIG. 5 (e), the fiber reinforcing members (1) are mutually deformed in the portion where the layers are overlapped with each other to fill the gap. Further, since the fiber reinforcing material (1) can be easily deformed into an arbitrary cross-sectional shape, for example, as shown in FIG. is there.

Thereafter, the above-mentioned curable resin (10) is cured, taken out of the mold, and integrated with the other half to form the main girder (7). A urethane foam or the like is arranged around the main girder (7), and an FRP
Surface is formed into a windmill blade.

In the above-described embodiment, the formation of the main girder of the wind turbine blade has been described. However, the FRP molded body of the present invention can be applied to a bridge girder of a bridge, a panel constituting a large dome, or the like. It goes without saying that the present invention can be applied to various other FRP molded articles regardless of the type.

[0032]

Since the present invention is constructed and operates as described above, it has the following effects.

(1) Since the fiber-reinforced material is formed in a string shape, the fiber-shaped reinforcement material in the form of a string may be cut at a required length when the fiber-reinforced material is placed in a molding die. No cut loss unlike the technical roving cloth.
Therefore, the yield can be improved and the manufacturing cost of the FRP molded body can be reduced.

(2) Since the reinforcing material made of fiber is in a string shape, even if the forming die has a complicated curved surface shape, it can be bent freely to conform to the surface shape of the forming die, and the fiber bundle portion is braided. Since the fiber bundles are bundled by the sleeve part that has been deformed, the cross-sectional shape of the fiber bundle part is deformed without becoming loose or entangled, and it easily adapts to the surface shape of the molding die, so complicated shapes such as spiral shapes and many curved surfaces Thus, it is possible to easily cope with a three-dimensionally shaped molded body, and the design of the FRP molded body is facilitated.

(3) The fiber-reinforced material is in the form of a string, and can be simply and intensively arranged at a required portion such as a portion that bears bending simply by cutting it to a desired length. The weight can be reduced.

(4) For the fiber reinforcing material, it is only necessary to braid the sleeve portion around the fiber bundle portion formed by aligning the high-strength fibers, and a braiding device generally used can be used. Thus, the fiber reinforcing material can be manufactured at low cost.

(5) The fiber reinforcing material is in the form of a string and can be wound around a reel, so that it is easy to handle.
Unlike the conventional roving cloth, it is only drawn linearly and does not require a large working space for cutting.

(6) When the fiber bundle has an inter-fiber member between high-strength fibers, the inter-fiber member forms an infiltration path for the curable resin, so that the impregnation of the resin can be improved. Since the displacement of the high-strength fiber is facilitated and the fiber-reinforced material is easily bent and the cross-sectional shape is easily deformed, the familiarity with the molding die can be further improved. Further, when the inter-fiber member has a cushioning performance, a restoring force to a perfect circle is generated in the fiber-reinforced material, so that the impregnation performance is further improved,
It is possible to reduce habits such as twisting, and to improve workability.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing an embodiment of a fiber reinforced material for FRP of the present invention.

FIG. 2 is an enlarged sectional view of a fiber bundle portion.

FIG. 3 is a sectional view showing a schematic shape of a fiber-reinforced material,
FIG. 3A is a cross-sectional view of the fiber reinforcement after braiding, and FIGS.
FIG. 3E is a cross-sectional view of the fibrous reinforcing member in a state deformed by the pressing force in the diameter direction.

FIG. 4 shows an embodiment in which the FRP molded body of the present invention is applied to a main girder of a windmill blade, and FIG. 4 (a) is a perspective view in which a part of a half part of the main girder is omitted, and FIG. 4 (b). FIG. 4 is an enlarged sectional view of a main part of a half part.

FIG. 5 is a cross-sectional view showing a schematic shape of a fiber-reinforced material arranged in a molding die, and FIG. 5 (a) is a cross-sectional view of the fiber-reinforced material in a state where no pressing force is applied; 5 (b) to 5 (e) are cross-sectional views of the fiber-reinforced material deformed by the pressing force in the diameter direction.

FIG. 6 is a cross-sectional view of a fibrous reinforcing material embedded in a groove of a molding die.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fiber reinforcement material for FRP, 2 ... High-strength fiber (glass roving), 3 ... Fiber bundle part, 4 ... Sleeve part, 5 ... Braided yarn, 6 ... Inter-fiber member, 7 ... FRP molded body (Windmill blade Main digits).

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C08L 101: 00 B29C 67/14 X (72) Inventor Yoshito Tabuchi 43 Saiin, Ukyo-ku, Kyoto-shi, Kyoto No. 1 Chun-Ei Heights 215 F-term (reference) 3H078 AA02 BB21 CC02 4F072 AA04 AA07 AB03 AB06 AB09 AB10 AB15 AB30 AB33 AD03 AD23 AD38 AL17 4F205 AA36 AD16 AD18 AD20 AH04 AH47 HA19 HA33 HA44 HB01 HC01 HC02 HC07 HC10 HC14 HC01 HC01 HC02 HC07 HC10 HC14 HC AA24 BA05 BB00

Claims (13)

[Claims] 1. A fiber bundle (3) formed by aligning high-strength fibers (2), and a tubular sleeve (4) disposed around the fiber bundle (3). FRP characterized in that said sleeve portion (4) is formed by braiding with a braided yarn (5).
Fiber reinforcement for use. 2. The high-strength fiber (2) forming the fiber bundle portion (3) comprises at least one fiber selected from glass fiber, carbon fiber and aramid fiber. The fiber reinforced material for FRP according to the above. 3. The fiber bundle (3) has a diameter of 10 to 30.
The fiber reinforced material for FRP according to claim 1 or 2, which is mm. 4. The braid density of the sleeve portion (4) is such that the high-strength fibers (2) of the fiber bundle portion (3) are bundled together and the high-strength fibers (2) are displaced in the diameter direction. The fiber bundle part (3)
The fiber reinforced material for FRP according to any one of claims 1 to 3, which has a roughness that allows deformation of the cross-sectional shape of the FRP. 5. The FR according to claim 4, wherein the sleeve portion (4) is formed by braiding 16 to 64 braided yarns (5).
Fiber reinforcement for P. 6. The fiber bundle part (3) has inter-fiber members (6) between the high-strength fibers (2...).
The fiber reinforced material for FRP according to any one of the above. 7. The fiber reinforced material for FRP according to claim 6, wherein the high-strength fiber (2) in the fiber bundle portion (3) is 50% by weight or more. 8. The fiber reinforced material for FRP according to claim 6, wherein the inter-fiber member (6) is made of a fiber material. 9. The fiber reinforced material for FRP according to claim 6, wherein the inter-fiber member (6) is made of a granular material. 10. The fiber reinforced material (1) for FRP according to any one of claims 1 to 9, which is arranged along the direction of the stress applied to the molded body (7). An FRP molded product obtained by curing and molding the curable resin impregnated in (1). 11. The FRP formed body according to claim 10, wherein the formed body is a main girder of a blade for a windmill. 12. The FRP molding according to claim 10, wherein the molding (7) is a bridge. 13. The FRP molded body according to claim 10, wherein said molded body (7) is a panel constituting a dome.