JPS61138743A - Reinforcing material for fiber reinforced resin and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a reinforcing material for fiber-reinforced resins, and more particularly to a reinforcing material suitable as an intermediate base material for reinforcing strong resins using glass fibers or carbon fibers. be.

[Prior art and its problems]

In the case of fiber-reinforced resins used in applications where torsional loads are applied in the plane direction of a plate-shaped object, such as the skin material of airplane wings, the reinforcing material for the fiber-reinforced resin is one in which the reinforcing fibers also intersect in the bias direction. It is preferable that the

A common method for reinforcing fibers to intersect in the bias direction is to bias-cut and laminate unidirectional prepreg, which is made by aligning general warp and warp fabrics or reinforcing fibers in one direction and impregnating them with resin, but this method results in a large amount of cut loss. This is very troublesome as it makes it impossible to continue the work. Furthermore, sufficient strength cannot be obtained because the reinforcing fibers are not continuous in the bias direction. Alternatively, there is a problem in how the layers are stacked, which may cause variations in physical properties if they are not placed adjacent to each other with high precision.

Furthermore, as a means to make the lamination continuous, there is a fabric in which reinforcing fibers cross each other in the bias direction, but since this fabric does not have continuous fibers in the longitudinal direction, when tension is applied in the longitudinal direction, the fabric will move in the bias direction. There are problems in that the intersection angle of the arranged reinforcing fibers changes and density unevenness occurs, making it extremely difficult to handle.

[Purpose of the invention]

The purpose of the present invention is to overcome the drawbacks of the prior art as mentioned above,
To provide a reinforcing material for fiber-reinforced resin, which is a woven material configured so that reinforcing fibers intersect even in the bias direction, but has a stable form, and does not cause uneven strength when made into fiber-reinforced resin. That is.

[Structure of the invention]

In order to achieve the above object, the present invention has the following technical configuration. That is, it is composed of at least two warp yarn groups, and both yarn groups are laminated at an angle other than 0° or 90'' to each other in a planar cross state without being crossed or bent. A reinforcing material for fiber-reinforced resin characterized in that both groups of yarns are integrated by auxiliary yarns intersecting each other with a weaving structure, and at least two groups of warp yarns are arranged at an angle of 90" to each other. After producing a fabric body which is cross-laminated without intersecting or bending each other, and in which both yarn groups are integrated by intersecting auxiliary yarns with a weave structure, the fabric body is folded in the middle direction of the fabric body. This is a method for producing a reinforcing material for fiber-reinforced resin, which is characterized in that the reinforcing material is taken at a certain angle.

To summarize the basic technical idea of the present invention, a reinforcing material for fiber-reinforced resins needs to be strong against torsion (with little deformation and isotropic), and the laminated bias cut method is required for this purpose. Although this type of method is commonly used, it is impossible to achieve continuity, high speed, and homogenization, so one group of warp yarns of the reinforcing fibers is made continuous.
This yarn group is made to intersect with another yarn group at an arbitrary angle, and in order to create this structure, warp yarn groups consisting of two reinforcing fibers are warped in advance by a normal method so as to cross each other by approximately 90 degrees.
The above-mentioned cloth body is made by making a cloth that crosses each other in a shape similar to that of ``1'', and then taking it off while bending it at a predetermined angle.

[Function of the invention]

The invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 shows an example of a reinforcing material for fiber-reinforced resin obtained by the present invention. (2), 2 are reinforcing fibers made of glass fiber or carbon fiber, and 3.4 are auxiliary threads made of glass fiber or polyaramid fiber. One warp group made of carbon fiber 2 etc. and the auxiliary yarn 4 intersect at an angle α with respect to the yarn axis direction of the other warp yarn group made of carbon fiber 1 etc. and the auxiliary yarn 3, and the angle α is 90 °less than 20”
-70'', more preferably 45°. Further, the angle α may be -20' to -70°.

In the present invention, among the reinforcing materials thus obtained,
2 to 10 sheets with arbitrary intersection angles are selected as needed, stacked and integrated, and then impregnated with resin. More specifically, there are two types: one with a constant intersection angle, one with an opposite intersection angle (the former can be used inside out), and the conventional one with an intersection angle of 90°. It is possible to combine and integrate the reinforcing fiber yarn group and the reinforcing fiber thread group.

In this case, continuity can be easily achieved by overlapping all the reinforcing materials in the direction of the continuous yarn group among the warp yarn groups of each reinforcing material.

For example, 45° direction, -45° direction, O° direction and 90°
A reinforcing material reinforced in four axes can be obtained by sequentially laminating a plurality of sheets in different directions (unbiased original fabrics) and integrating them by stitching or the like.

In Figure 2, ■ is one of the warp yarn groups made of carbon fiber (multifilament) that does not have bends that would cause stress concentration, and when manufacturing, this yarn group can be used as warp yarns. many. 2 is a carbon fiber (multifilament) that does not have bends that cause stress concentration, similar to 1.
This is another group of warp threads consisting of warp threads, and is often used as weft threads in manufacturing. Both thread groups are in a crossing state without crossing each other. Reference numeral 3 denotes an auxiliary thread disposed at an intermediate position of the carbon fiber group 1, which is made of glass fiber (multifilament) or polyaramid fiber (multifilament). Similarly to 3, auxiliary threads 3 and 4 are made of glass fiber (multifilament) or polyaramid fiber (multifilament) and are placed in the middle of carbon fiber group 2, and each of the auxiliary threads 3 and 4 mutually form a plain weave structure. The carbon fibers 1.2 are held in one body by crisscrossing the carbon fibers that are perpendicular to each other in a bent state.

By adopting the above-mentioned structure, carbon fibers can exist in a substantially unbent state, and glass fibers and polyaramid fibers have high strength and high elasticity, and have a sufficiently large elongation at break compared to carbon fibers. Because of this, when stress is applied, even if the stress is concentrated on the auxiliary yarn, the auxiliary yarn will not break before the carbon fibers break.

Therefore, the excellent properties of carbon fiber such as high strength and high elasticity can be used without any loss.

Another major characteristic is that the carbon fibers in both warp yarn groups are not interlaced and are layered in a flat manner, making them extremely easy to shift in the bias direction, and providing excellent stability in that state. It is.

FIG. 3 shows one method of continuously bias-processing the fabric described above, 5 and 5' are supply nip rollers, 6 is the fabric explained in FIG. 2, and 7 is a winding device.

The fabric body 6 is passed at right angles to the supply nip roller 5.5' and then at an angle α of 20° to 70° or -20° to -70° with respect to the central axis of the supply nip roller 5.5'.
The unidirectional bias reinforcing material of the present invention is obtained by taking off the fabric obliquely in the direction of 0 and then winding it at right angles to the length of the taken fabric. In practice, the take-off angle α is preferably 45° or -45°.

The width of the fabric obtained by this bias processing is the original fabric width W1, and the fabric width W2 after processing is in the relationship W2 = W1 cos α, and when the bias angle α = 45°, the original fabric width is one block of the required width. Requires twice the width.

FIG. 4 shows an example of obtaining a four-axis reinforced structure using the reinforcing material for fiber-reinforced resin of the present invention, 8 is a reinforcing raw fabric without bias processing in the 0° direction and 90'' direction, 9 is 4
The reinforcing material for fiber-reinforced resin of the present invention is bias-processed in the 5° direction, and 10 is the reinforcing material for fiber-reinforced resin of the present invention that is bias-processed in the -45° direction. Here, the −45° bias processed product can be obtained by turning the 45° bias processed product upside down.

Each reinforcing material 8.9.10 is continuously wound into rolls, each placed parallel to each other, unrolled with rotation to perform successive layers, then stitched with stitch needle 12 and stitch thread. By stitching and integrating the parts 13, a reinforcing structure in four axial directions can be obtained continuously. The stitch thread used for stitching is preferably polyaramid fiber or low shrinkage polyester fiber, which hardly shrinks at the prepreg processing temperature (120° C. to 180° C.).

〔Effect of the invention〕

(1) Since the carbon fibers, which are reinforcing fibers, are arranged in the bias direction, the strength in the bias direction is improved, and a plate-like body that is resistant to twisting can be obtained.

(2) Since carbon fibers, which are reinforcing fibers, are arranged in the longitudinal direction of the fabric, they do not deform even when tension is applied in the longitudinal direction, allowing continuous lamination, which greatly improves work efficiency. Highly accurate lamination is possible.

(3) Each warp yarn group of reinforcing fibers, such as carbon fibers, intersects without being interlaced or bent, and is woven with auxiliary threads, so the reinforcing fibers, such as carbon fibers, do not bend. Because the fibers spread well, the excellent properties of carbon fibers such as high strength and high elasticity can be used without any loss.

(4) Since there are no intersecting points in both warp yarn groups such as carbon fibers, which are reinforcing fibers, stability after bias processing is excellent.
Enables highly accurate lamination and stitching.

(5) Glass fibers or polyaramid fibers are used as the auxiliary yarns that unify the reinforcing fibers such as carbon fibers, so the temperature (
120°C to 180°C), it hardly shrinks, so it has almost no effect on the carbon fibers that are reinforcing fibers.

Example Carbon fiber “Trading Card” T-300 manufactured by Toshi Co., Ltd. (number of filaments: 3000, cross-sectional area: 0.112 m++2.),
Glass fiber EC0450110 manufactured by Nittobo Co., Ltd. (number of filaments: approx. 200. Cross-sectional area: 0.0044a+m2)
and prepared.

Next, using a rapier loom, the carbon fibers and glass fibers are alternately arranged as warp yarns, and one carbon fiber and one glass fiber are alternately driven in from the weft direction with a rapier, so that the carbon fibers and glass fibers are Each density is 6.0 in the vertical direction
The fabric body (A) has a structure shown in Fig. 2, with a thread/am and a width of 2.1 threads/cs, and the warp threads are only made of glass fibers, and the weft threads are made of only carbon fibers, and are implanted with a rapier.
The density is 6.0 in the vertical direction, 7 countries, and 3.0 in the horizontal direction.
A fabric body CB) having a plain weave structure designated as e11 was obtained.

The fabric body (A) is placed in the bias processing machine shown in FIG. 3, and is fed perpendicularly to the supply nip roller 5.5', so that the angle between the center axis of the supply nip roller 5.5' and the warp direction of the fabric body is The warp threads are taken off at an angle of 45 degrees, and then wound at right angles to the take-up direction.
A fabric body was obtained in which the weft yarns were biased at 45° in the ° direction.

At this time, the supply nip roller 5 is replaced with a metal smooth roller.
The top side 5' was a rubber roller, the metal roller 5 was driven, and the roller surface speed was 10 m/n+in. Furthermore, the take-up and winding roller 7 was provided with a large flange that matched the width of the taken-up woven fabric to regulate its width.

In addition, a power clutch was provided between the winding rollers 7 to drive the winding rollers 7, and the winding was carried out so that the tension of the taken-up textile body was always constant.

Next, the three types of rolls of the fabric body (A) obtained by the bias processing, the front side and the back side, and the fabric body (B), are arranged as shown in FIG. Made of polyaramid fiber 200D (Kevlar 29, number of filaments 134, cross-sectional area 0.031III+2)
The fabric was integrated by stitching at a density of l stitches/c11 in both the vertical and horizontal directions.

The thus obtained laminate was impregnated with an epoxy resin, pressed and cured to obtain CFRP. The obtained CFRP exhibited substantially uniform strength in all directions in the plane, and exhibited physical properties of high torsional rigidity.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram showing an example of the reinforcing material for fiber-reinforced resin of the present invention. FIG. 2 is a diagram showing the structure of the amount of raw fabric used in the reinforcing material for fiber-reinforced resin of the present invention. FIG. 3 is a perspective view of bias processing snowmaking, and FIG. 4 is a schematic diagram of a method for manufacturing a laminate using the reinforcing material of the present invention. 1.2... Carbon fiber, 3.4... Glass fiber or polyaramid fiber (auxiliary yarn), 5.5'... Supply nip roller, 6... Original fabric, 7... Winding roller, 8
... 0°, 90° woven fabric, 9.10... Fabric body after bias processing, 11... Stitched laminate, 12.
... Stitch needle, 13... Stitch thread.

Claims (8)

[Claims] (1) It is composed of at least two groups of warp yarns, and both groups of yarns are laminated at an angle other than 0° or 90° to each other and intersect in a plane without being crossed or bent, and A reinforcing material for fiber-reinforced resin, characterized in that both of these thread groups are integrated by auxiliary threads that intersect with each other in a weave structure. (2) The reinforcing material for fiber-reinforced resin according to claim 1, wherein at least a part of the warp yarn group is carbon fiber. (3) The reinforcing material for fiber-reinforced resin according to claim 1, wherein the auxiliary yarn is a type of fiber selected from glass fiber and polyaramid fiber. (4) The reinforcing material for fiber-reinforced resin according to claim 1, wherein the intersecting angle of both warp thread groups is 20° to 70°. (5) At least two groups of warp yarns are cross-stacked at an angle of 90° to each other without intersecting or bending, and both groups of yarns are integrated by intersecting auxiliary yarns with a weaving structure. 1. A method for producing a reinforcing material for fiber-reinforced resin, which comprises producing a fabric and then taking the fabric at a certain angle to the width direction of the fabric. (6) The method for manufacturing a reinforcing material for fiber reinforced resin according to claim 5, wherein the take-up angle is 20° to 70°. (7) It is composed of at least two groups of warp yarns, and both groups of yarns are laminated at an angle other than 0° or 90° to each other and in a planar crossing state without being crossed or bent, A reinforcing material for a fiber-reinforced resin, characterized in that a fabric body in which both yarn groups are integrated by auxiliary yarns that intersect with each other in a weaving structure is laminated and integrated with another fabric body. (8) The reinforcing material for fiber-reinforced resin according to claim 7, wherein the other fabric body is composed of two groups of warp threads intersecting each other at an angle of approximately 90°.