JP2001279554A - Reinforced fiber woven fabric and method of weaving the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforced fiber woven fabric capable of being easily subjected to opening treatment to give a tight woven fabric, and to provide a method of weaving the same. SOLUTION: This reinforced fiber woven fabric is composed of warp and weft consisting of carbon fiber multifilament yarn, wherein plural warp threads and/or weft threads are woven to be arranged into the same design point. The method of weaving the reinforced fiber woven fabric comprises weaving the carbon fiber multifilament yarn which is used as the warp and the weft, wherein plural threads of the weft pass through the same shed formed by the warp threads moving up and down in a loom. Further, continuous plural threads of the warp pass through the same heald moving up and down to be woven into the fabric.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforced fiber woven fabric using carbon fibers, which exhibits excellent characteristics as an aircraft structural composite material, and a method for producing the same. The present invention relates to a woven fabric and a method for producing the woven fabric.

[0002]

2. Description of the Related Art As a fiber reinforced composite material, a reinforced fiber woven fabric using carbon fiber, glass fiber, aramid fiber or the like is used. Above all, many low-weight reinforced fiber woven fabrics using carbon fibers and methods for producing the same have been proposed so far, and a shuttle loom or a rapier loom is usually used for the production. The woven fabric is often used as a reinforcing material for a composite material such as carbon fiber reinforced plastic by impregnating with a synthetic resin and molding into a predetermined shape.

However, a low-weight fabric having a basis weight of about 100 to 200 g / m ² in which warp yarns and weft yarns are alternately crossed one by one like a conventional flat structure is shown in FIG.
As shown in (1), the fabric is usually an apertured fabric in which an opening 33 is formed between the warp yarn 31 and the weft yarn 32. For example, warp yarns and weft yarns composed of multifilament yarns of 3K (3000 carbon fibers) or 6K or 12K carbon fibers are alternately interleaved one by one, woven by plain weave, and having a basis weight of 95 to 250 g / m ^2.
Usually has an opening ratio of 15 to 30%.

In such a woven fabric having openings, resin voids are intensively formed in the openings during molding or prepreg processing, and the strength of the fiber-reinforced plastic obtained from the woven fabric is reduced. There was a problem. Therefore, it is indispensable to perform a certain opening process during or after weaving to obtain a woven fabric having as few openings as possible as shown in FIG. 5B, that is, a woven fabric having a small opening ratio.

[0005]

As a method of producing a reinforcing fiber woven fabric having a small opening ratio, for example, a method of vibrating and spreading warp yarns to form a low-weight woven fabric, or a method of continuously forming a woven fabric and then forming the same. The method of opening the yarn by fluid treatment is
It is disclosed in JP-A-7-300738. Further, as another manufacturing method, Japanese Patent No. 2895185 proposes a method of correcting a mesh formed in a cloth having a relatively low density by rolling and moving a spherical body under a pressurized state.

[0006] However, there is a problem that the opening property of the multifilament yarn of carbon fiber is greatly affected by its physical properties. For example, in order to improve the weaving property, it is necessary to use a thread having a low hook drop value, a thread having a twist, a thread having a large amount of sizing agent attached, or taking measures such as increasing the adhesive strength of the sizing agent. On the contrary, since the spreadability generally deteriorates, there are very few yarns satisfying both the weaving property and the spreadability at present. Here, the hook drop value is a value obtained by measuring the distance that a weight attached to a metal hook is hooked on the upper portion of the carbon fiber having the upper and lower ends fixed to the vertical direction, and the free fall distance is short ( The lower the hook drop value, the better the filament entanglement and the convergence, but the yarn opening properties are generally poor.

On the other hand, if flat yarns are used instead of carbon fiber multifilament yarns, the fiber opening step becomes unnecessary. However, there is a drawback in that it is necessary to change the yarn width of the flat yarn to be used depending on the target basis weight of the woven fabric, and it is necessary to arrange various types of flat yarn.

Accordingly, an object of the present invention is to provide a reinforced fiber woven fabric which can be easily opened into a non-perforated woven fabric even when a multifilament yarn of carbon fiber having relatively low spreadability is used, and a reinforced fiber woven fabric thereof. It is to provide a manufacturing method. Another object of the present invention is to provide a reinforced fiber woven fabric having a low basis weight and a low opening ratio, and a prepreg capable of obtaining a high-strength, lightweight fiber-reinforced composite material.

[0009]

That is, the reinforcing fiber woven fabric of the present invention is a reinforced fiber woven fabric comprising carbon fiber multifilament yarns as warp yarns and weft yarns, wherein the warp yarns and / or the weft yarns have the same structure. It is characterized by weaving each. Further, the reinforcing fiber woven fabric of the present invention,
The basis weight is desirably 250 g / m ² or less. In addition, the reinforcing fiber fabric of the present invention is desirably subjected to fiber opening treatment and has an opening ratio of 5% or less. The prepreg of the present invention is characterized in that the reinforced fiber fabric of the present invention is impregnated with a synthetic resin.

The method for producing a reinforced fiber woven fabric according to the present invention is a method for producing a reinforced fiber woven fabric in which a multifilament yarn of carbon fibers is used for warp and weft yarns. It is characterized in that a plurality of weft threads are inserted into the same mouth to be made.
Further, the method for producing a reinforced fiber woven fabric of the present invention is a method for producing a reinforced fiber woven fabric in which weaving is performed using a multifilament yarn of carbon fiber as a warp and a weft. It is characterized by weaving through a heald that does

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The reinforcing fiber woven fabric of the present invention is obtained by weaving a plurality of warp yarns and / or weft yarns composed of multifilament yarns of carbon fibers in the same structure. As the reinforcing fiber woven fabric of the present invention, for example, those having a single-circulation woven fabric structure as shown in FIG. In the one-circle woven fabric structure shown in FIG. 1, (A) is a woven fabric structure in which both warp and weft yarns are continuously formed in the same structure, and (B) is a woven fabric structure in which only two weft yarns are continuously formed in the same structure. (C) is a fabric structure in which only two warp yarns are continuously arranged in the same structure.

The reinforced fiber woven fabric represented by the woven structure shown in FIG. 1A has, for example, two warp yarns and two weft yarns each composed of multifilament yarns of 3K, 6K or 12K carbon fibers. It is arranged inside. The reinforcing fiber woven fabric represented by the woven structure of FIG. 1 (B) is obtained by arranging two wefts continuously in the same structure. For example, when a 6K or 12K multifilament yarn is used as a warp yarn Two wefts consisting of 3K or 6K multifilament yarns are arranged continuously. The reinforcing fiber woven fabric represented by the woven structure of FIG. 1 (C) is one in which two warp yarns are continuously arranged in the same structure. For example, when a 6K or 12K multifilament yarn is used as a weft yarn. Two continuous warp yarns composed of multifilament yarns of 3K or 6K.

The carbon fibers used in the reinforcing fiber fabric of the present invention may be those used in conventional carbon fiber fabrics, and are not particularly limited. The fineness may also be appropriately selected according to the use of the reinforcing fiber fabric.

In the reinforcing fiber woven fabric of the present invention, it is necessary to make the sum of the fineness of each yarn at the intersection of the warp yarn and the weft yarn equal, that is, to make the yarn width the same. This is preferable because the strength balance between the horizontal direction and the horizontal direction is improved. In addition, by making the sum of the fineness of the warp and the weft fine the same, the intersection of the warp and the weft becomes positive, and a woven product with a beautiful appearance can be obtained. There are advantages such as that a woven form can be obtained. However, depending on the application, the sum of the fineness of the warp and the sum of the fineness of the weft may be different.

The basis weight of the reinforced fiber fabric of the present invention is not particularly limited, but is preferably 250 g / m ² or less in order to obtain a lightweight fiber reinforced composite material.

The reinforcing fiber woven fabric of the present invention is preferably subjected to a fiber opening treatment. By performing the fiber opening treatment, it is possible to obtain a fiber-reinforced composite material that does not generate voids when impregnated with a synthetic resin and has high strength.
For example, the reinforcing fiber woven fabric woven with the woven structure shown in FIG. 1 (B) has a difference in the degree of opening, but usually, as shown in FIG. 2 (1), between the warp yarn 1 and the weft yarn 2. Opening 3
Having. The reinforcing fiber woven fabric having such openings is
During molding or prepreg processing, resin voids are intensively generated in the openings 3 and reduce the strength of the fiber-reinforced plastic obtained from this woven fabric. It is preferable to use a reinforcing fiber woven fabric having no openings as shown in FIG.

Examples of the method of the fiber opening treatment include a method of vibrating the warp yarn during weaving, a method of performing air jet or water jet treatment on the woven fabric, a method of opening with a rotating sphere, and a method of resin opening. For example, a method of opening the fiber while interposing the same. Comparison between the case where two or more warp yarns and / or weft yarns are continuously arranged in the same structure as in the present invention and the case where the warp yarns and the weft yarns are alternately interleaved one by one like a conventional flat structure. Then, even if the same aperture is used, it is better to continuously arrange a plurality of fibers with the same structure to improve the spreadability. This is because, when there are many aggregates of the filament yarn, the movement between the filaments is increased by the impact from the outside, so that the filament is easily broken and the opening effect is very likely to appear.

In order to improve the spreadability, it is necessary to make the opening conditions strict in any method. However, when the multifilament yarn of carbon fiber receives abrasion or impact from the side with respect to the longitudinal direction of the fiber, the damage is increased, the filament is cut, and the strength and appearance are poor. Therefore, it is necessary to perform the fiber opening treatment while considering the opening ratio and the strength physical properties of the reinforcing fiber woven fabric.

The opening ratio of the reinforcing fiber fabric of the present invention is at least 10% or less, preferably 5% or less. The opening ratio here is a ratio of the sum of the areas of the openings where neither the warp nor the weft are present in the unit area to the unit area of 100 mm × 100 mm. The sum of the areas of the openings of the reinforcing fiber fabric can be measured using, for example, a commercially available image processing sensor (CV-100, manufactured by Keyence Corporation). The aperture ratio can be obtained by the following formula. Opening ratio = sum of opening areas / □ 100 mm area × 100
(%)

The reinforcing fiber woven fabric of the present invention may be, for example, a yarn obtained by using a 12K multifilament yarn as a warp yarn and continuously arranging two weft yarns composed of a 6K multifilament yarn in the same structure. , If you open it,
It looks like a woven fabric obtained by using a warp and a weft consisting of a multifilament yarn of 12K carbon fiber. However, when the weft of the reinforcing fiber fabric is decomposed, it can be clearly identified that two multifilament yarns of 6K carbon fiber are arranged. This is because, during the opening process, the width between the single fibers (between the filaments) is widened almost in parallel, and not all the filaments are involved.

The prepreg of the present invention can be produced by impregnating the reinforcing fiber fabric of the present invention with a synthetic resin. As the synthetic resin, for example, a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, and a phenol resin, and a thermoplastic resin such as a nylon resin, a polyester resin, and a polybutylene terephthalate resin can be used. The proportion of the synthetic resin impregnated in the reinforcing fiber fabric is 30 to 60% by weight based on the obtained prepreg.

Next, a method for producing a reinforced fiber fabric according to the present invention will be described. FIG. 3 is a schematic view showing an example of a loom used for manufacturing the reinforcing fiber fabric of the present invention. The multifilament yarn of carbon fibers supplied from the creel 11 is regulated in a sheet shape by the comb 12 so as not to intersect with the adjacent yarn. The bundle of multifilament yarns arranged in a sheet shape by the comb 12 is fed from a guide 13 to a nip roller 14,
15 through a plurality of bending guides 16 to the healds 17 and 18 which move up and down. Furthermore, it is drawn into the reed 19 which regulates the fabric width and the warp yarn density. At this time,
The healds 17 and 18 are sequentially moved up and down, and the weft is intermittently inserted into the mouth formed by the up and down movement of the warp with a shuttle or rapier (not shown) to form a woven fabric. This woven fabric is wound up by a winding roller 20.

The fabric structure of the fabric woven in this manner is determined by how the warp yarns pass through the healds 17 and 18, how the healds move up and down, and how weft yarns are inserted into the mouth. For example, in the woven fabric represented by the woven structure shown in FIG. 1A, first, a plurality of arranged warp yarns are alternately passed through the heald 17 and the heald 18 in advance in the order in which they are arranged. In the above, the healds 17 and 18 are sequentially moved up and down, two weft yarns in the mouth formed by the vertical movement of the warp yarns are continuously inserted, and then the heald 17 and the heald 18 are formed when the vertical relationship is reversed. It is manufactured by continuously inserting two weft yarns in the mouth different from the above, and repeating this alternately.

In the woven fabric represented by the woven texture shown in FIG. 1B, first, a plurality of arranged warp yarns are alternately passed through healds 17 and 18 one by one in the order in which they are arranged. At the time of weaving, the healds 17 and 18 are sequentially moved up and down, two weft yarns are continuously inserted in the mouth formed by the vertical movement of the warp yarns, and then formed when the vertical relationship between the healds 17 and 18 is reversed. It is manufactured by continuously inserting two weft yarns in the mouth different from the above, and repeating this alternately.

In the woven fabric represented by the woven texture shown in FIG. 1C, first, a plurality of arranged warp yarns are alternately passed through the heald 17 and the heald 18 in advance in the order of arrangement. During weaving, the healds 17 and 18 are sequentially moved up and down, and weft yarns are inserted one by one into the mouth formed by the vertical movement of the warp yarns.

In the method for producing a reinforced fiber woven fabric according to the present invention, the warp yarn is subjected to a widening treatment such as abrasion, vibration opening, air opening, etc., so that the woven fabric has as few openings as possible before opening. Is preferred. Among them, the effect of widening,
In consideration of the uniform widening, the widening processing by the vibration opening technique is most preferable. By subjecting the warp yarn to the widening process, a woven fabric having an opening ratio of about 10% is obtained, and the subsequent fiber opening process is facilitated. It should be noted that even if the weft yarn is subjected to the widening process, the effect is not so obtained because it is converged by the beating process.

The reinforcing fiber woven fabric obtained by the production method of the present invention is preferably subjected to the above-mentioned fiber opening treatment. The reinforcing fiber woven fabric having openings as shown in FIG.
And a reinforcing fiber woven fabric without openings.

In the method for producing a reinforcing fiber woven fabric according to the present invention, the warp yarn is supplied by a beam supply method,
As shown in the illustrated example, there is a method of directly supplying from a creel, and in each method, a required number is wound on a beam or arranged in a creel. In addition, as a creel supply method,
A method in which the bobbin around which the multifilament yarn of carbon fiber is wound is slowly rotated to pull out and unwind the yarn in a direction perpendicular to the rotation axis (horizontal capture), and to draw and unwind the yarn in the axial direction of the bobbin Two methods (vertical taking) are adopted. Here, in the vertical take-up and unwinding method, one twist is applied every time the yarn is drawn out, and there is a possibility that the opening process during or after weaving may be hindered. Therefore, intercepting supply from creel is most preferable.

[0029]

Embodiments are described below. In this example, carbon fibers (Pyrofil manufactured by Mitsubishi Rayon Co., Ltd.) were used as the warp and weft.

[Example 1] 3K (fineness 1800)
Using a denier (multi-filament) yarn, 1K (fineness 60
(0 denier) multifilament yarns were inserted three by three, and a reinforcing fiber woven fabric having a basis weight of 100 g / m ² was woven. After weaving of the reinforcing fiber woven fabric, as shown in FIG. 4, a steel plate 22 arranged horizontally and a running path of the reinforcing fiber woven fabric W are arranged below the steel plate 22 and a large number of steel balls 2 are arranged on the upper surface thereof.
Excitation table 2 in which 3 are arranged and vibrates in the vertical direction
4 and a frequency of 30H.
z, amplitude 1.2 mm, supply speed 1 m / min,
Opening treatment was applied to the reinforced fiber fabric. After opening the reinforcing fiber fabric, the opening ratio was measured. Table 1 shows the results.

As a result of subjecting the reinforcing fiber woven fabric to a fiber opening treatment, a reinforcing fiber having a good fiber opening property and a very small opening was obtained with respect to an opening ratio of 25% of the unopened woven fabric. When the reinforcing fiber fabric was impregnated with an epoxy resin, a prepreg having no voids was obtained.

Comparative Example 1 Warp and weft yarns were 3K
Using a multifilament yarn having a fineness of 1800 denier, a flat fiber reinforced fiber woven fabric having a basis weight of 100 g / m ² was woven. Opening treatment was performed on the reinforcing fiber woven fabric under the same conditions as in Example 1, but the opening ratio was 8% due to poor openability. Further, when the reinforced fiber woven fabric was impregnated with an epoxy resin, voids were generated due to large voids between the fibers. Table 1 shows the results.

Example 2 Warp yarns of 6K (fineness 3600)
(Denier) multifilament yarn, and 3K (fineness 18) is formed in the same mouth formed by the vertical movement of the warp yarn.
(00 denier) multifilament yarn was inserted two by ^{two, and} a reinforced fiber woven fabric having a fabric structure as shown in FIG. 1B and a basis weight of 200 g / m ² was woven. As a result of subjecting the reinforcing fiber woven fabric to the fiber opening treatment under the same conditions as in Example 1, a reinforcing fiber having a good fiber opening property and an extremely small opening was obtained. When the reinforcing fiber fabric was impregnated with an epoxy resin, a prepreg having no voids was obtained. Table 1 shows the results.

Comparative Example 2 6K warp and weft yarns
Using a multifilament yarn having a fineness of 3600 denier, a flat-fiber reinforced fiber woven fabric having a basis weight of 200 g / m ² was woven. Opening treatment was performed on the reinforced fiber fabric under the same conditions as in Example 1, but the openability was poor. Further, when the reinforced fiber woven fabric was impregnated with an epoxy resin, voids were generated due to large voids between the fibers. Table 1 shows the results.

Example 3 Warp yarns of 12K (fineness 720
(0 denier) multifilament yarn, 6K (fineness 3) in the same mouth formed by the vertical movement of the warp yarn.
Weft yarns consisting of multifilament yarns (600 deniers) were inserted two by ^{two, and} a reinforced fiber woven fabric having a fabric structure as shown in FIG. 1B and a basis weight of 200 g / m ² was woven. As a result of subjecting the reinforcing fiber woven fabric to the fiber opening treatment under the same conditions as in Example 1, a reinforcing fiber having a good fiber opening property and an extremely small opening was obtained. When the reinforcing fiber fabric was impregnated with an epoxy resin, a prepreg having no voids was obtained. Table 1 shows the results.

Example 4 Two warp yarns of multifilament yarn of 6K (fineness: 3600 denier) are continuously passed through a heald that moves up and down in the same direction, and 6K (fineness) is formed in the same opening formed by the vertical movement of the warp yarns. Weft yarns consisting of multifilament yarns (3600 deniers) were inserted two by ^{two, and} a reinforcing fiber woven fabric having a fabric structure as shown in FIG. 1A and a basis weight of 200 g / m ² was woven.
As a result of subjecting the reinforcing fiber woven fabric to the fiber opening treatment under the same conditions as in Example 1, a reinforcing fiber having a good fiber opening property and an extremely small opening was obtained. In particular, it has been found that a woven fabric in which a plurality of warp yarns and weft yarns are woven is more effective in spreading. When the reinforcing fiber fabric was impregnated with an epoxy resin, a prepreg having no voids was obtained. Table 1 shows the results.

Comparative Example 3 Warp and weft yarns of 12K
Using a multifilament yarn having a fineness of 7200 denier, a reinforced fiber woven fabric having a basis weight of 200 g / m ² was woven. Opening treatment was performed on the reinforced fiber fabric under the same conditions as in Example 1, but the openability was poor. Further, when the reinforced fiber woven fabric was impregnated with an epoxy resin, voids were generated due to large voids between the fibers. Table 1 shows the results.

[0038]

[Table 1]

[0039]

As described above, the reinforced fiber woven fabric of the present invention is formed by weaving a plurality of warp yarns and / or weft yarns in the same structure, so that the multifilament made of carbon fibers having relatively poor spreadability. Even in the case of using a yarn, it is possible to easily open a woven fabric having no openings. If the basis weight of the reinforcing fiber fabric is 250 g / m ² or less, a lightweight fiber-reinforced composite material can be obtained. Further, if the fiber opening treatment is performed and the opening ratio is 5% or less, the resin is uniformly impregnated between the carbon fiber yarns when impregnated with the synthetic resin, has no voids, and has high strength. A fiber reinforced composite material can be obtained.

Since the prepreg of the present invention is obtained by impregnating the reinforced fiber fabric of the present invention with a synthetic resin, a high-strength and lightweight fiber-reinforced composite material can be obtained. Further, the method for producing a reinforcing fiber woven fabric of the present invention is a method in which a plurality of weft yarns are inserted into the same opening formed by the vertical movement of the warp yarns during weaving, so that the woven fabric can be easily opened into a nonwoven fabric. Thus, a reinforced fiber fabric that can be obtained can be obtained. In addition, since the method for producing a reinforcing fiber woven fabric of the present invention is a method of weaving a plurality of continuous warp yarns through a heald that moves up and down in the same manner, it is easy to open the woven fabric without openings. A reinforced fiber fabric that can be obtained can be obtained.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a single-circle woven structure diagram showing an example of a reinforcing fiber woven fabric of the present invention, in which (A) is a woven fabric diagram in which two warp yarns and weft yarns are continuously formed in the same structure, and FIG. )
Is a woven fabric diagram in which only two weft yarns are continuously arranged in the same structure, and (C) is a woven fabric diagram in which only two warp yarns are continuously arranged in the same structure. Indicates that the warp is on the weft.

FIG. 2 is a diagram showing an example of a reinforcing fiber fabric of the present invention, wherein (1) is a diagram showing a reinforcing fiber fabric having an opening between a warp and a weft, and (2) is a diagram without openings It is a figure showing a reinforcing fiber textile.

FIG. 3 is a schematic view showing an example of a loom used for producing the reinforcing fiber fabric of the present invention.

FIG. 4 is a perspective view showing an example of a fiber opening device used for manufacturing the reinforcing fiber fabric of the present invention.

FIG. 5 is a view showing an example of a conventional reinforcing fiber fabric;
(1) is a diagram showing a reinforcing fiber fabric having an opening between a warp and a weft, and (2) is a diagram showing a reinforcing fiber fabric having no openings.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Warp yarn 2 Weft yarn 17 Heald 18 Heald W Reinforced fiber fabric

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Samejima 4-160 Sunadabashi, Higashi-ku, Nagoya-shi, Aichi F-term in Merchandise Research Laboratory, Mitsubishi Rayon Co., Ltd. 4F072 AA04 AA07 AA08 AB10 AB18 AB28 AD13 AD23 AD37 AD38 AD44 AG03 AK05 AK14 AL02 4L048 AA05 AB07 BC04 DA41

Claims (6)

[Claims] 1. A reinforced fiber woven fabric comprising a carbon fiber multifilament yarn as a warp and a weft, wherein a plurality of the warp and / or the weft are woven in the same structure. 2. The reinforcing fiber woven fabric according to claim 1, wherein the basis weight is 250 g / m ² or less. 3. The reinforcing fiber woven fabric according to claim 1, wherein a fiber opening treatment is performed and an opening ratio is 5% or less. 4. A prepreg obtained by impregnating the reinforced fiber woven fabric according to claim 1 with a synthetic resin. 5. A method for producing a reinforced fiber woven fabric using a multifilament yarn of carbon fiber as a warp yarn and a weft yarn, wherein a plurality of weft yarns are formed in the same mouth formed by the vertical movement of the warp yarns during weaving. A method for producing a reinforcing fiber woven fabric, comprising inserting. 6. A method for producing a reinforced fiber woven fabric using carbon fiber multifilament yarns as warp yarns and weft yarns, wherein a plurality of continuous warp yarns are woven by passing through a heddle having the same vertical movement. A method for producing a reinforced fiber woven fabric.