JP4067855B2 - Fiber-reinforced resin plate with improved bending strength in the longitudinal direction - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fiber-reinforced resin plate-like material called a so-called FRP, and particularly to a fiber-reinforced resin plate-like material with improved bending strength in the longitudinal direction, which is preferably used as a wind turbine blade for wind power generation. .
[0002]
[Prior art]
Conventionally, fiber-reinforced resin plates are used for wind turbine blades of wind power generation, rotor blades of helicopters, or fixed wings such as main wings and tail wings of airplanes. In particular, in a rotary blade such as a wind turbine blade, a large bending stress is generated in the longitudinal direction of the blade due to centrifugal force and air resistance.
[0003]
For this reason, what improved the bending strength in the longitudinal direction of a wing | blade is requested | required. For example, Japanese Patent Application Laid-Open No. 64-63132 and Japanese Patent Application Laid-Open No. 6-74142 propose a method in which a large number of reinforcing fibers are arranged in the longitudinal direction of the blade and the bending strength in the longitudinal direction is improved by the reinforcing fibers. ing. However, even if the reinforcing fiber is thick, it is about several tens of deniers, and it has been difficult to dramatically improve the bending strength in the longitudinal direction.
[0004]
[Problems to be solved by the invention]
Therefore, the present inventor has intensively studied to obtain a fiber-reinforced resin plate-like material having dramatically improved bending strength in the longitudinal direction. I came up with a method of inserting a fiber-reinforced resin rod in the direction. In general, fiber reinforced resin (FRP) has very high strength, and the idea of further strengthening FRP with some material does not occur. However, the present inventor obtained an idea that did not exist before, such as inserting FRP further into FRP against such common sense. Then, was repeated research to realize this idea, if pinched in particular reinforcing fibrous structure with a fiber-reinforced resin rod readily can Rukoto injects the fiber-reinforced resin rod, in the longitudinal direction The present inventors have found that a fiber-reinforced resin plate having improved bending strength can be obtained, and have reached the present invention.
[0005]
[Means for Solving the Problems]
That is, in the present invention, a plurality of fiber reinforced resin rods arranged in parallel and in the longitudinal direction at predetermined intervals are sandwiched between at least two reinforcing fiber structures arranged on the upper surface and the lower surface thereof. After that, it is a fiber reinforced resin plate made by impregnating the entire resin , and at least one of the reinforcing fiber structures includes a layer A in which all reinforcing fibers are aligned in a certain direction, and all reinforcing fibers. In particular, the present invention relates to a fiber-reinforced resin plate-like material with improved bending strength in the longitudinal direction, wherein at least two layers are laminated with a layer B aligned in another predetermined direction. is there.
[0006]
A conventionally known fiber reinforced resin rod 1 used in the present invention is used. The cross-sectional shape of the fiber reinforced resin rod 1 may be arbitrary, and may be, for example, a circle, an ellipse, a quadrangle, or a triangle. A circular shape is most preferable for improving the bending strength.
[0007]
The fiber reinforced resin rod 1 is manufactured by a conventionally known method. For example, it can be obtained by impregnating a reinforcing fiber bundle such as glass fiber roving with resin, coating it on a glass fiber mat impregnated with resin, and then molding and curing the resin in a thermoforming mold. Yes (continuous pultrusion method). As the reinforcing fiber, carbon fiber or the like can be used in addition to glass fiber. As the resin, an unsaturated polyester resin, an epoxy resin, or the like can be used. The weight ratio of the reinforcing fiber and the resin is generally larger than the weight ratio of the reinforcing fiber, and is about reinforcing fiber: resin = 60 to 95:40 to 5.
[0008]
Since the reinforcing fiber structure 2 is disposed on the upper and lower surfaces of the fiber reinforced resin rod 1 and sandwiches the fiber reinforced resin rod 1, at least two sheets are necessary. At least one of the two sheets is formed by laminating at least two layers of a layer A in which all the reinforcing fibers are aligned in a certain direction and a layer B in which all the reinforcing fibers are aligned in another certain direction. It will be. Such a reinforced fiber structure 2 can be manufactured by a device called “COPCENTRA MAX 3 CNC” manufactured by LIBA (FIG. 3) or a device called “multi-axial model 14024” manufactured by Meyer. By using these apparatuses, it is possible to easily obtain the reinforcing fiber structure 2 in which the reinforcing fiber layer A arranged in a certain direction and the reinforcing fiber layer B arranged in another certain direction are laminated. In the example shown in FIG. 3, the reinforcing fibers are supplied from four locations, the reinforcing fiber layers arranged in the longitudinal direction, the reinforcing fiber layers arranged in the width direction, and 45 ° to the left (+ 45 °) with respect to the longitudinal direction. ), And a four-layer reinforcing fiber structure 2 is obtained by laminating a reinforcing fiber layer arranged in the direction of 45 ° to the right (−45 °) with respect to the longitudinal direction. Yes. If the number of reinforcing fiber supply points is increased in the apparatus of FIG. 3, a multilayer reinforcing fiber structure can be obtained, and if the number of reinforcing fiber supply points is decreased, two or three layers of reinforcing fiber structures can be obtained. A structure is also obtained. A conventionally well-known thing is used as another reinforcing fiber structure which can be used together with such a reinforcing fiber structure 2 . For example, a reinforcing fiber mat or a chopped strand mat (a collection of reinforcing fibers cut into a predetermined length) is used.
[0009]
In the present invention, since the bending strength is particularly improved in the longitudinal direction, the reinforcing fiber structure 2 including the reinforcing fiber layer A arranged in the longitudinal direction and the reinforcing fiber layer B arranged in the width direction is used. Is preferred. This is because the reinforcing fiber layer A improves the bending strength in the longitudinal direction even slightly. Further, since the reinforcing fiber layer A alone is difficult to handle, the reinforcing fiber layer B is laminated, and both layers A and B are sewn with sewing threads and integrated. Any manner of sewing may be used, but they may be integrated while knitting a chain yarn of Russell knitting. In addition, it may be sewn with a sewing machine.
[0010]
Further, since the improvement in the bending strength in the longitudinal direction can be sufficiently achieved by the fiber reinforced resin rod, in order to improve the bending strength in the bias direction to some extent, the reinforcement arranged in the direction of 45 ° to the left with respect to the longitudinal direction. It is preferable to use the reinforcing fiber structure 2 including the fiber layer A and the reinforcing fiber layer B arranged in the direction of 45 ° to the right with respect to the longitudinal direction. The two layers A and B can improve the bending strength in both bias directions to some extent. Moreover, if both layers A and B are sewn with a sewing thread, they are integrated and easy to handle. As in the example shown in FIG. 3, when the four-layer reinforcing fiber structure is used, the bending strength is slightly improved in both the width direction and the both bias directions, and the width direction and the both biases are particularly improved. The bending strength is balanced depending on the direction, which is preferable.
[0011]
Glass fiber, carbon fiber, etc. are employ | adopted for the reinforcing fiber which comprises the reinforcing fiber structure 2. FIG. When the reinforcing fiber structure is obtained with the apparatus shown in FIG. 3, generally, a rowing in which long glass fibers (glass fiber strands) or long carbon fibers (carbon fiber strands) are bundled is used. Deniers such as glass fiber are optional, and the weight of the rowing is also optional. In addition, when the other reinforcing fiber structure used together is a reinforcing fiber mat or a chopped strand mat, the glass fiber or carbon fiber is generally cut to an appropriate length.
[0012]
The prepared fiber reinforced resin rods 1 are arranged in parallel and in the longitudinal direction on the reinforcing fiber structure 2 at a predetermined interval as shown in FIG. Is done. Next, as shown in FIG. 2 (ii), the reinforcing fiber structure 2 is disposed on the upper surfaces of the plurality of disposed fiber reinforced resin rods 1, 1. As a result, the reinforcing fiber structures 2, 2 are arranged on the upper and lower surfaces of the arranged fiber reinforced resin rods 1, 1,. The reinforcing fiber structures 2 and 2 arranged on the upper surface and the lower surface may be the same type or different types. In general, two reinforcing fiber structures 2 and 2 are arranged on the upper surface and the lower surface, that is, two reinforcing fiber structures 2 and 2, for example, three on the lower surface and one on the upper surface. The above reinforcing fiber structure may be arranged. Here, a single reinforcing fiber structure means that it can be handled as a single piece, and is a multilayered reinforcing fiber structure manufactured by the apparatus shown in FIG. 3, and the layers are integrated by sewing threads. A thing means one piece as a whole.
[0013]
Next, as shown in FIG. 2 (iii), the reinforcing fiber structures 2 and 2 are sewn with the sewing thread 3 between the fiber reinforced resin rods 1 and 1 arranged in parallel. In FIG. 2, there is one sewing location between the fiber reinforced resin rods 1, 1..., For example, two or more locations may be sewn with the sewing thread 3. 2 shows an example in which sewing is performed at an intermediate position between the fiber reinforced resin rods 1, 1..., Rather, the reinforcing fiber structure 2 is sewn on both sides in the vicinity of the fiber reinforced resin rod 1. , 2 are easy to adhere to each other, which is preferable. A conventionally known sewing thread 3 is used as the sewing thread 3, but a polyester thread is preferably used from the viewpoint of heat resistance and strength. It is also preferable to use carbon fiber yarn or glass fiber yarn. The manner of sewing in this case is also arbitrary. For example, it may be integrated while knitting a chain stitch yarn of Russell knitting or by sewing with a sewing machine. As described above, the fiber reinforced resin rods 1, 1... Are sandwiched between the reinforcing fiber structures 2 and 2, and the whole is integrated.
[0014]
The integrated product in which the fiber reinforced resin rods 1, 1... Are sandwiched between the reinforcing fiber structures 2 and 2 is impregnated with resin. The impregnation method may be performed by a conventionally known method. For example, a method of immersing in a resin bath or a method of applying a resin many times is adopted. As this resin, similarly to the case of the resin used for the fiber reinforced resin rod 1, an unsaturated polyester resin, an epoxy resin, or the like can be used. The amount of resin impregnation is also arbitrary, but if the weight of the integrated product is 100 parts by weight, it is preferably about 50 to 150 parts by weight. In particular, the resin impregnation amount is most preferably about the same as the weight of the integrated product.
[0015]
If the resin is cured by a predetermined method after impregnating the resin, the fiber-reinforced resin plate-like material according to the present invention can be obtained. Here, the plate-like object means that the plate-like object is substantially flat, and does not deny that a curved surface exists. For example, even if there are a large number of curved surfaces and twists of wind turbine blades of wind power generation and helicopter rotor blades, they are almost flat and are included in the plate-like object according to the present invention. In addition, a large number of curved surfaces and twists are provided on the main wing and tail wing of an airplane, and this case is also included in the plate-like object according to the present invention.
[0016]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to an Example.
[0017]
Example First, by using the apparatus shown in FIG. 3, the reinforcing fiber layer A arranged in the longitudinal direction and the reinforcing fiber layer B arranged in the width direction were laminated, and both layers A and B were chain-knitted with polyester yarn. And sewed and integrated to obtain a reinforcing fiber structure having a width of 1.27 m. At this time, the reinforcing fibers used to prepare both layers A and B are rowing (2.2 g / m) made of long glass fibers (strands). And each layer A and B was adjusted so that it might become 433 g / m < ² >, respectively.
[0018]
On the other hand, the fiber reinforced resin round bars obtained by the continuous pultrusion method are parallel to each other with an interval of 10 mm, and the longitudinal direction of the fiber reinforced resin round bars coincides with the longitudinal direction of the reinforcing fiber structure. Then, it was arranged on the reinforcing fiber structure. This round bar has a diameter of 2.95 mm and a weight of 14.64 g / m. The reinforcing fiber is a glass fiber, and its content is 79% by weight. The resin is a thermosetting unsaturated polyester resin that is heat-cured at 140 ° C.
[0019]
Next, a commercially available chopped strand mat having a basis weight of 450 g / m @ 2 was placed on the upper surface of the fiber reinforced resin round bars arranged in parallel. This chopped strand mat is obtained by depositing chops obtained by cutting glass strands into about 1 inch and hardening them with unsaturated polyester resin. This chopped strand mat is also a reinforcing fiber structure.
[0020]
As described above, the state shown in FIG. 2 (ii) is obtained, and then one point between the fiber reinforced resin round bars is sewn while knitting a chain knitting yarn with a polyester yarn, and is obtained by the apparatus shown in FIG. The fiber reinforced resin round bars arranged in parallel were sandwiched between the reinforced fiber structure and the reinforced fiber structure made of the chopped strand mat to obtain an integrated product. The weight of this integrated product was 2800 g / m ² . The polyester yarn is also used to integrate the laminated reinforcing fiber structure obtained by the apparatus shown in FIG. 3, and is also used to obtain an integrated product. Is 20 g / m ² .
[0021]
This integrated product was impregnated with a resin composition composed of 100 parts by weight of an unsaturated polyester resin (“5836P-2” manufactured by Nippon Iupika Co., Ltd.) and 1 part by weight of acetylacetone peroxide as a curing agent. The impregnation amount of the resin composition was such that the resin composition was 117 parts by weight with respect to 100 parts by weight of the integrated product. And it was left to stand for 20 minutes or more in 12-15 degreeC atmosphere, and the unsaturated polyester resin was hardened.
[0022]
A three-point bending test defined in JIS K 7055 was performed on the longitudinal direction of the fiber-reinforced resin plate-like material obtained as described above. As a result, the maximum stress was 238 MPa and the elastic modulus was 6.16 GPa.
[0023]
Comparative Example An integrated product was obtained in the same manner as in Example except that the fiber reinforced resin round bar was not used. The weight of this integrated product was 1336 g / m ² . Then, this integrated product was impregnated with the resin composition used in the examples. The amount of impregnation was such that the resin composition was 108 parts by weight with respect to 100 parts by weight of the integrated product. Thereafter, the unsaturated polyester resin was cured in the same manner as in the Example to obtain a fiber-reinforced resin plate. When this fiber reinforced resin plate was subjected to the same three-point bending test as in the example, the maximum stress was 181 MPa and the elastic modulus was 3.62 GPa.
[0024]
As is clear from the comparison between the fiber reinforced resin plate obtained in the example and the fiber reinforced resin plate obtained in the comparative example, both the maximum stress and the elastic modulus of the example are better. It can be seen that the bending strength in the longitudinal direction is high.
[0025]
【The invention's effect】
As described above, since the fiber reinforced resin plate-like product according to the present invention has a fiber reinforced resin rod inserted and integrated in the longitudinal direction, the bending strength in the longitudinal direction can be improved. Play. At least one of the reinforcing fiber structures to be used is at least two layers of a layer A in which all the reinforcing fibers are aligned in a certain direction and a layer B in which all the reinforcing fibers are aligned in another certain direction. Therefore, the thickness and physical properties of the reinforcing fiber structure can be changed as appropriate, and the desired fiber-reinforced resin plate-like product can be obtained.
[0026]
Further, the fiber-reinforced resin plate according to the present invention is an integrated product in which a fiber-reinforced resin rod is sandwiched between at least two reinforcing fiber structures, and the fiber-reinforced resin rod is sewn with a sewing thread. If it is impregnated with a resin, it can be easily obtained. That is, since the fiber-reinforced resin rod and the reinforcing fiber structure are integrated, it is easy to handle, and any resin impregnation method can be employed.
[0027]
Further, as the reinforcing fiber structure used in the present invention, there are at least two layers of a layer A in which all reinforcing fibers are aligned in a certain direction and a layer B in which all reinforcing fibers are aligned in another certain direction. If the layer A and the layer B are sewn with sewing threads, they can be handled as a single piece regardless of how the thickness and physical properties of the reinforcing fiber structure are changed. The desired fiber-reinforced resin plate can be obtained.
[0028]
In addition, if the same type is used as the fiber and resin constituting the fiber reinforced resin rod, the reinforcing fiber constituting the reinforcing fiber structure, and finally the resin to be impregnated, each is more firmly integrated. There is an effect that a fiber-reinforced resin plate-like material is obtained. For example, if all the fibers are glass fibers and all the resins are polyester unsaturated resins, it is possible to obtain a fiber-reinforced resin plate-like product that is more uniformly integrated as a whole.
[Brief description of the drawings]
FIG. 1 is a perspective view of a fiber-reinforced resin plate according to an example of the present invention.
FIG. 2 is a side view showing a part of a procedure for obtaining a fiber-reinforced resin plate according to an example of the present invention.
FIG. 3 is a perspective view showing an optimum apparatus for obtaining a reinforcing fiber structure used in the present invention.
[Explanation of symbols]
1 Fiber reinforced resin rod 2 Reinforced fiber structure 3 Sewing thread

Claims (7)

After sandwiching a plurality of fiber reinforced resin rods arranged in parallel and in the longitudinal direction at a predetermined interval with at least two reinforcing fiber structures arranged on the upper surface and the lower surface thereof, the resin is entirely added. It is a fiber reinforced resin plate impregnated , and at least one of the reinforcing fiber structures includes a layer A in which all reinforcing fibers are aligned in a certain direction, and all reinforcing fibers are in another certain direction. A fiber-reinforced resin plate having improved bending strength in the longitudinal direction, wherein at least two layers of the layer B and the layer B aligned in the above are laminated .   2. A fiber with improved bending strength in the longitudinal direction according to claim 1, wherein at least two reinforcing fiber structures are sewn with sewing threads between adjacent fiber reinforced resin rods, and the fiber reinforced resin rods are sandwiched between the fibers. Reinforced resin plate. Fiber reinforced fibers constituting the layer A is being aligned in the longitudinal direction, the reinforcing fibers constituting the layer B, which is improved longitudinal bending strength according to claim 1, wherein are aligned in the width direction Reinforced resin plate. The reinforcing fibers constituting the layer A are aligned in the + 45 ° direction with respect to the longitudinal direction, and the reinforcing fibers constituting the layer B are aligned in the −45 ° direction with respect to the longitudinal direction. A fiber-reinforced resin plate-like product having improved bending strength in the longitudinal direction according to claim 1 . Fiber-reinforced resin plate-like workpiece in the longitudinal direction of the bending strength is improved according to claim 1 wherein in which a layer A and layer B is sewn by sewing thread.   2. The fiber-reinforced resin plate-like product with improved bending strength in the longitudinal direction according to claim 1, wherein the fibers contained in the fiber-reinforced resin rod are glass fibers, and the fibers constituting the reinforcing fiber structure are also glass fibers. .   The resin in the fiber reinforced resin rod is obtained by curing an unsaturated polyester resin, and the resin impregnated throughout is also an unsaturated polyester resin. The fiber reinforced resin with improved bending strength in the longitudinal direction according to claim 1 Plate.

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