JP3279255B2 - Flat yarn woven fabric - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat yarn woven fabric which exhibits excellent properties as a fiber composite material. More particularly, the present invention relates to a flat yarn woven fabric using a flat carbon fiber yarn and having a uniform fiber density.

[0002]

2. Description of the Related Art A carbon fiber woven fabric made of carbon fibers having a large specific elastic modulus and a large specific strength is usually woven by a general shuttle loom or rapier loom, and is formed into a predetermined shape by compounding with a synthetic resin. By being molded, it is frequently used as a reinforcing base material for composite materials such as carbon fiber reinforced plastic (hereinafter, referred to as “CFRP”).

[0003] As such a reinforcing base material for composite materials, for example, CFRP has begun to be used for structural materials of aircraft, etc. by taking advantage of its excellent performance. However, in order to further expand the use range of CFRP, A major issue is not only the molding but also the cost reduction of intermediate substrates such as carbon fibers and carbon fiber fabrics.

[0004] As the carbon fiber becomes thicker and the fineness becomes larger, the productivity in the precursor and the flame-proofing step and the firing step is improved, and it becomes possible to produce inexpensive carbon fiber yarn.

[0005] However, in a normal carbon fiber woven fabric, a carbon fiber yarn converged to a substantially circular cross section is used as a woven yarn to make the woven fabric. Therefore, in a woven state, the carbon fiber in the intersection where the warp yarn and the weft yarn intersect is formed. The cross section of the yarn is elliptical, and the woven yarn is heavily crimped. In particular, in a carbon fiber woven fabric using a thick carbon fiber yarn, this tendency is large because the thick weft yarn and the thick warp yarn are crossed.

[0006] Therefore, in a carbon fiber woven fabric in which the carbon fiber yarn as the woven yarn is large crimped, the fiber density becomes non-uniform and the high strength characteristics characteristic of carbon fiber cannot be sufficiently exhibited. In addition, carbon fiber woven fabric using thick carbon fiber yarn,
Generally, since the fabric weight and the thickness increase, the resin impregnating property when molding a prepreg or a fiber reinforced plastic (hereinafter, referred to as “FRP”) deteriorates.

[0007] Therefore, CFRP obtained by using a carbon fiber woven fabric using a thick carbon fiber yarn has a large number of voids in the resin, so that high strength characteristics cannot be expected.

On the other hand, in a carbon fiber woven fabric having a small basis weight using a thick carbon fiber yarn, a void formed between the carbon fiber yarns becomes large. For this reason, when CFRP is formed using a carbon fiber woven fabric having a small basis weight, the content of carbon fiber yarns is low, and voids of resin are intensively generated in voids formed between carbon fiber yarns. There was a drawback that CFRP could not be obtained.

In order to solve such a disadvantage, Japanese Patent Application Laid-Open No. 58-1912
No. 44 discloses a thin woven fabric having a thickness of 0.09 mm or less and a basis weight of 85 g / m ² or less woven of a thin and wide flat carbon fiber yarn, and a method for producing the same. Since the thin fabric is very thin, it has a small crimp of the woven yarn, exhibits a high reinforcing effect, and is an excellent base material for forming a thin CFRP.

The method of weaving a carbon fiber woven fabric using flat carbon fiber yarns as described above is based on a warp beam supplied from a warp beam wound with a required number of carbon fiber yarns or a carbon fiber yarn bobbin set on a creel. Are sequentially opened by healds, and wefts are inserted into the openings by a shuttle or rapier.

As for the warp yarn, there are a beam supply method and a method of directly supplying the warp yarn from the bobbin. In either case, the carbon fiber yarn bobbin is unwound while being slowly rotated or unwound in the axial direction of the bobbin. There are two methods of unwinding.

In addition, since the supply speed of the weft yarn is much faster than that of the warp yarn, there is only a method of unwinding the warp yarn from the bobbin. Japanese Patent Laid-Open No. 2-746 discloses a method for unwinding and unwinding a weft yarn so that the flat yarn is not twisted.
No. 45 proposes a method in which a bobbin is positively rotated by a motor and the length required for weft insertion is stored using gravity.

[0013]

By the way, when a bobbin on which a flat yarn is wound is unwound vertically and unwound, a single twist is applied every time the bobbin makes one round, and the flat state is crushed and partially broken. There is a problem of convergence. On the other hand, even if the yarn is unwound and fed so as not to be twisted, the flat state is crushed by the comb for equalizing the warp yarn density and the mail of the heald, and a woven fabric having a uniform yarn width cannot be obtained.

Further, regarding the weft yarn, Japanese Patent Laid-Open No. 2-74
According to the method disclosed in Japanese Patent No. 645, the weft is unwound, so that the weft is not twisted. However, in the method of actively rotating the bobbin, the unwinding speed varies depending on the winding amount, so that the starting and stopping are frequent. In particular, there is a problem that the flat yarn is twisted due to slackness caused by a delay in the stopping operation.

Furthermore, in order to reduce the crimp of the woven yarn at the intersection of the warp and the weft, the fibers constituting the woven yarn must be as fine as possible and the woven yarn must be a flat yarn having a small thickness. It is preferable that the warp and the weft have a woven structure with a yarn interval substantially equal to the respective yarn width.

However, when the fibers of the woven yarn become thick, the yarn width becomes extremely wide, and the flat state is crushed during weaving, so that there is a problem that a woven fabric having a uniform fiber density cannot be obtained. Further, when the woven yarn is an extremely narrow and thin flat yarn, there is a problem that the rigidity in the yarn width direction is reduced and the flat state is easily collapsed during weaving. In this case, it is conceivable to attach a sizing agent in order to maintain the flat state of the woven yarn. However, if a large amount of the sizing agent is attached, impregnation of the resin during molding of CFRP is impeded, and the molded CFRP is high There is a problem that the strength characteristics cannot be exhibited.

Further, in the thin fabric disclosed in Japanese Patent Application Laid-Open No. 58-191244 and a method for producing the same, an enormous number of fabric bases or fabric prepregs are laminated on the formation of medium or thick CFRP. Because you have to
There are drawbacks in that the CFRP to be molded is expensive and the molding operation is very troublesome.

As described above, conventionally, it has not been possible to mold CFRP having excellent strength characteristics when the carbon fiber is thick.

The present invention has been made in view of the above points, and it is an object of the present invention to improve the disadvantages of the prior art, and to provide a reinforcing base for FRP in which the flat state is maintained even with a flat yarn made of a thick yarn. It is an object of the present invention to provide a flat yarn woven fabric which is inexpensive and can exhibit high strength characteristics.

[0020]

According to the carbon fiber (hereinafter referred to as "CF") flat yarn woven fabric of the present invention, the fineness is 3,000 to 20,000 denier and the yarn width is 4 mm.
～16Mm, yarn width / Itoatsumi ratio is 30 or more pre-emption unwinding,
A warp and a weft consisting of CF flat yarn to which a sizing agent is attached, the pitch of which is 1.0 to 1.2 times the yarn width, and the fiber density is 0.8 g / cm ³ or more. It was done. Preferably, the CF flat yarn has an adhesion amount of the sizing agent in the range of 0.5 to 2.5% by weight. Also preferably, the CF flat yarn woven fabric has a woven fabric weight of 100.
The woven fabric thickness is in the range of 0.1 to 0.4 mm within the range of 300300 g / m ² .

[0021] Preferably, the warp and weft yarns have substantially no crimp.

The first and second CF flat yarn woven fabrics are impregnated with 30 to 67% by weight of a synthetic resin to form a prepreg.

Further, the first and second CF flat yarn fabrics are fiber-reinforced plastics containing 30 to 67% by weight of a matrix resin.

The above-mentioned CF flat yarn woven fabric is a woven fabric in which warp yarns and weft yarns composed of CF flat yarns are crossed, and the woven fabric structure is not particularly limited. However, even in a structure such as a plain weave in which each yarn alternates one by one alternately and the crimp tends to be large, the crimp of the yarn is extremely small because the yarn itself is actually flat and thin. It is kept small and the strength characteristics do not deteriorate.

[0025] CF flat yarn is used in the fiber manufacturing process.
Before the sizing process, the fiber bundle consisting of multiple fibers may be arranged in a ribbon shape, and the shape may be retained with a sizing agent and wound on a bobbin, or the flat yarn may be opened in a separate process to form a ribbon shape. And may be fixed with a sizing agent.

In particular, carbon fiber yarns have high strength and high elasticity, but when the woven yarn is crimped as described above, the high strength characteristics of carbon fibers cannot be sufficiently exhibited. For this reason, in order to obtain a carbon fiber woven fabric having a small crimp ratio of the woven yarn and a uniform fiber density, it is necessary to use a thin and flat carbon fiber yarn and to make the woven fabric at a pitch substantially equal to the yarn width.

Therefore, the fibers constituting the CF flat yarn have a fineness of 3,000 to 20,000 deniers, and the yarn thickness is preferably 0.05 to 0.2 mm, the yarn width is preferably 4 to 16 mm, and the yarn width is 4 to 16 mm. It is preferred that the yarn / yarn thickness ratio be 30 or more.

In order to maintain the flat shape, the flat yarn should have a thickness of 0.
5 to 2.5 by attaching weight% of a small amount of sizing agent <br/> Contact Ku.

The condition is that the CF flat yarn has no twist. If the flat yarn is twisted, the yarn width becomes narrower and converges at the twisted portion and becomes thicker, and irregularities occur on the surface of the woven fabric. For this reason, in the woven fabric, when an external force acts, stress concentrates on the twisted portion, and the FRP
When formed into a uniform shape, the strength characteristics become non-uniform.

Conventionally, even when a high-performance CF flat yarn is used, high strength characteristics cannot be sufficiently exhibited due to a large crimp of the woven yarn. Since the flat yarn woven fabric of the present invention uses the flat yarn, the crimp of the woven yarn is small, and the high strength characteristics of the fiber are exhibited from the viewpoint of the woven structure.

In this case, as the properties of the CF flat yarn used, the tensile elongation at break must be large and the tensile elongation at break must be high. The tensile elongation at break is 1.5 to 2.3% and the tensile elongation at break is 20%.
0-800kg ・ f / mm ² , tensile modulus is 20,000〜70,000k
g · f / mm ² is desirable.

The flat yarn woven fabric woven by using the warp yarns and the weft yarns composed of the CF flat yarns has a woven structure substantially equal to the respective yarn widths, whereby a gap is formed at the intersection where the warp yarns and the weft yarns intersect. There is almost no woven fabric with high fiber density.

However, in the woven flat yarn woven fabric, since the warp and the weft are actually interlaced, it is difficult to make the yarn interval equal to the yarn width. Therefore, in the woven flat yarn woven fabric, the space between any one of the warp yarn and the weft yarn may be equal to the yarn width, and the interval between the other yarns may be slightly larger than the yarn width. However, if the yarn interval is
If it exceeds 1.2 times, the voids become so large that a woven fabric having a high fiber density cannot be obtained. For this reason, it is desirable that the yarn interval between the warp yarn and the weft yarn is 1.0 to 1.2 times the yarn width.

Here, the fiber density refers to a value defined by the following equation.

Fiber density (g / cm ³ ) = [textile weight (g / m ² )] /
[Woven fabric thickness (mm)]

The fabric weight (g / m ² ) and the fabric thickness (mm)
Is a value measured according to JIS R7602 carbon fiber fabric test method.

The flat yarn woven fabric of the present invention has a basis weight of 100 when woven from a warp yarn composed of CF flat yarn and a weft yarn.
To 300 g / m ^2, textile thickness 0.1 to 0.4 mm, when the weaving from the warp or weft made of CF flat yarn, and other auxiliary yarn, basis weight 90 to 200 g / m ^2, thickness 0 .1 to 0.3 mm.

At this time, when the yarn having a fineness of 3,000 to 20,000 denier is used, if the basis weight is less than 100 g / m ² ,
Weaving a flat yarn woven fabric with a CF flat yarn having a very high degree of flatness makes it difficult to weave, and even if weaving can be performed, the flat state of the flat yarn is crushed, resulting in a very coarsely woven fabric. On the other hand, if the basis weight is larger than 300 g / m ² , the impregnating property of the synthetic resin at the time of molding into prepreg or FRP is poor, and many voids are generated in the resin.

The flat yarn woven fabric of the present invention satisfies the above conditions and has a fiber density defined by the above-mentioned formula of 0.8 g / g.
Characteristically, it is not less than cm ³ .

In general, the strength characteristics of FRP depend on the volume content of fibers, and in particular, FRP using carbon fiber woven fabric substrates
In order to obtain high strength characteristics in the above, a woven fabric substrate having a high fiber density is required. Here, the volume content of fibers in FRP or the like refers to the volume ratio of the fiber base material to the volume of FRP, and is expressed by the following equation.

Fiber volume content (%) = [weight of fiber base material]
(g) / fiber density (g / cm ³ )] / [FRP volume (cm ³ )]

In this case, it is possible to obtain a carbon fiber woven fabric having a high fiber density by increasing the woven density of the carbon fiber yarn. However, conventionally, when the weaving density is increased, the crimp of the carbon fiber yarn in the carbon fiber fabric increases,
High strength CFRP was not obtained.

For this reason, in the conventional carbon fiber woven fabric, it was necessary to make the fiber density smaller than 0.8 g / cm ³ . In particular, when the carbon fiber is thick and its fineness is large, the fiber density of the woven fabric has to be further reduced.

The flat yarn woven fabric of the present invention uses CF flat yarn made of fibers having a high fineness, but the yarn width is 4 to 16 mm.
In yarn width / Itoatsumi ratio is 30 or more pre-emption unwinding, rhinoceros
The flat yarn to which the zing agent has adhered has a thread width approximately equal to 1.0.
~ 1.2 times yarn spacing, no untwisting and no carbon fiber flatness
It is woven in a state where the flat state of the yarn is maintained .
Therefore, the obtained flat yarn woven fabric minimizes the generation of voids and the crimp of the woven yarn, exhibits high fiber density, and exhibits high strength properties even when the fiber density is 0.8 g / cm ³ or more.

Prepreg or FR using the above-mentioned flat yarn woven fabric
P can be produced by impregnating a synthetic resin by a known method. The synthetic resin used at this time is a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, or a phenol resin, a nylon resin, a polyester resin, a polybutylene terephthalate resin, a polyetheretherketone (PEEK) resin, a bismaleimide resin, or the like. A thermoplastic resin can be used, and the flat yarn fabric is impregnated with 30 to 67% by weight of a synthetic resin.

[0046]

[Function] Fineness is 3,000 to 20,000 denier and thread width is 4 to
A warp yarn and a weft yarn composed of CF flat yarn having a yarn width / yarn thickness ratio of 30 mm or more and a sizing agent attached thereto are unwound at a pitch of 1.0 to 1.2 times the yarn width . Twist
Without the flat state of the carbon fiber flat yarn
Is woven, the fiber維密degree is a flat yarn woven on 0.8 g / cm ³ or more, the flat yarn woven fabric while maintaining a flat state without solution舒撚Ri is woven, even thick warp and weft In addition, the crimp in the intersecting portion is kept small, and the fiber density becomes uniform.

Further, the warp and weft made of CF flat yarn are woven with a very coarse yarn density, and the crimp of the woven yarn is small, so that it is easily deformed by shearing. That is, when the flat yarn woven fabric is subjected to shear deformation, there is enough room to close the yarn interval between the warp or weft yarns, so that the yarn width of the flat yarn is narrowed while the yarn interval is reduced, and the yarn is largely deformed without generating wrinkles. It is possible to follow a mold having a complicated shape.

In the case of the flat yarn woven fabric of the present invention, only the curved surface of the mold is subjected to shear deformation along the uniform woven fabric with small voids, so that the surface having a large curvature of the mold may be used. Uniformly high fiber coverage can be achieved.

A prepreg or FRP using the above-mentioned flat yarn woven fabric as a reinforcing base material has good resin impregnating property, so that it hardly generates voids in the resin and shows high strength characteristics.

[0050]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the flat yarn woven fabric of the present invention will be described below in detail with reference to FIGS.

FIG. 1 shows a manufacturing apparatus for manufacturing the flat yarn woven fabric of the present invention. The manufacturing apparatus includes a bobbin 1, a take-up roller 3, a tensioning device 4, and a weft supply device.
A guide roller 5 to 7, a leaf spring tension device 8, a push plate guide 9, a rapier 11, and the like are provided. As warp supply devices, a creel 20, a comb 21, a horizontal guide 2
2. The heald 23 and the reed 24 are provided.

First, a description will be given of a weft yarn supply device. The bobbin 1 is wound with a weft yarn _Twf made of carbon fiber flat yarn (hereinafter simply referred to as “flat yarn”), and the weft yarn _Twf is passed through a tension roller 2 to a weaving machine. And is unwound at a constant speed by the rotation of the take-up roller 3. Here, tension roller 2
Is located above when the weft thread _Twf is unwound from the bobbin 1 and automatically lowers when the loom stops,
The brake works and the inertial rotation stops.

[0053] unwinding speed of the weft T _wf can be easily determined if the loom rotational speed (rpm) and weft length required for one revolution (m) is known.

The flat yarn serving as the weft _Twf and the warp _Twr is
It is previously processed into a flat shape, is held in a form by a sizing agent or the like, and is wound around a bobbin 1 which is a cylindrical tube with a constant traverse width or bobbins 20a and 20b of a creel 20 described later. As the thickness of the yarn, the number of single carbon fiber yarns is 3,000 to 24,000, and the flatness of the yarn is 30 to 80 in a yarn width / yarn thickness ratio.

Then, the weft thread _Twf pulled out from the take-up roller 3 passes through the guide 4a of the tension device 4,
The guide is guided by the horizontal guide roller 5, the vertical guide roller 6, and the horizontal guide roller 7 and is guided to the leaf spring tension device 8.

Each of the guide rollers 5 to 7 preferably has a diameter of about 10 to 20 mm and a rotation system incorporating a bearing having a length of about 100 to 300 mm. If the diameter is too small, the carbon fibers constituting the weft yarn _{Twf tend} to bend and cause breakage of the single yarn. If the diameter is more than 20 mm, the inertia of rotation increases and the tension fluctuation at the time of starting and stopping increases. is there. In addition, each guide roller 5
The length of 7 must be such that the passing weft thread _Twf does not move in the left-right or up-down direction and does not contact the supporting portions supporting the guide rollers 5 to 7. Weft thread _Twf is guided by guide roller 5
When it comes into contact with the supporting portions of Nos. To 7, the flat state is crushed.

Horizontal guide roller 5 and guide roller 7
Determines the position of the weft _{Twf to be} guided in the height direction, and the vertical guide roller 6 determines the position of the weft _{Twf in} the horizontal direction. Therefore, the guide rollers at least in the horizontal direction and the vertical direction may be arranged alternately.

[0058] At this time, in and between the vertical guide roller 6 and the horizontal guide roller 5 and the vertical guide roller 6 and the horizontal guide roller 7, it is necessary to twist the flat surfaces of the weft T _wf 90 °. For this reason, the distance between the guide rollers 5 and 6 and the distance between the guide rollers 6 and 7 need to be separated by 50 mm or more, depending on the width of the weft thread _Twf . If the distance between the guide rollers is smaller than 50 mm, the weft thread _Twf will pass through the vertical guide roller 6 and the horizontal guide roller 7 while being twisted, and will be woven. In addition, the flat yarn is 90 ° at short distance
When twisted, tension is applied to both ends of the flat yarn, and fluff is generated.

The guide rollers 5 to 7 may be one, but if the weft thread _Twf is passed in an S-shape in two sets each, the tension acting on the weft thread _Twf is stabilized, and the weft thread Twf is stabilized. Positioning of _wf can be performed reliably.

The tension device 4 is provided with a rapier 11 described later.
When the weft _{Twf is} intermittently inserted, the slack between the take-up roller 3 and the horizontal guide roller 5 of the weft _Twf unwound at a constant speed by the take-up roller 3 is absorbed by the spring 4b, and the weft _Twf is absorbed. Is always nervous. Unless the weft thread _Twf is tensioned by the spring 4b, the weft thread _Twf is twisted when it is loosened, and there is a problem that the weft thread _Twwf passes through the guide rollers 5 to 7 and is woven. The guide 4a provided at the lower end of the spring 4b is arranged horizontally long so that the flat surface of the flat yarn is guided horizontally.

As another method for keeping the weft thread _Twf taut, there is a method using air suction. However, this method has a problem that the weft thread _Twf is twisted during suction. Further, in the method of tensioning the weft thread _Twf by weight, there is a problem that the tension fluctuation becomes too large and the carbon fibers constituting the weft thread _Twf are damaged, and the method using the spring is the simplest and reliable.

[0062] Further, on the downstream side of the horizontal guide roller 7 of the weft T _wf, tension device 8 which uniform tension of the weft T _wf is disposed. This tension device 8
By sandwiching the weft thread _Twf between the two wide leaf springs 8a and 8b, the tension of the weft thread _Twf is maintained uniformly.

In the weft supply method of the flat yarn woven fabric manufacturing apparatus according to the present invention, the weft path of the weft thread _Twf is determined in principle by the vertical guide roller 6. The yarn path of the weft thread _Twf may change due to the hooking operation. Therefore, even if the weft thread _Twf moves in the width direction, it is necessary that there is no object that interferes with the end of the weft thread _Twf , and for that, the wide leaf springs 8a and 8b are required.
Is used. Leaf springs 8a, 8b
_Should be at least five times the yarn width of the weft yarn _Twf .

The push plate guide 9 is arranged downstream of the weft thread _Twf of the plate spring tensioning device 8 and is a plate having a V-shaped guide surface 9a formed at the end. This guide 9
Is driven in the front-rear direction indicated by an arrow using a cam mechanism to which the rotation of the loom is transmitted in conjunction with the yarn feeding to the rapier 11.

In the vicinity of the downstream side of the push plate guide 9,
A yarn end gripping guide 10 is provided. As shown in FIG. 3, the yarn end gripping guide 10 has an L-shaped receiving member 10a and a pressing member 10b which is driven in a vertical direction by a driving unit (not shown). When the weft thread _Twf is supplied to the rapier 11, the guide member 10 descends in parallel with the forward movement of the push plate guide 9, and presses the weft thread _Twf against the receiving member 10a to grip the yarn end. ing.

Accordingly, the weft thread _Twf is lowered by the push plate guide 9 being pushed out in the direction of the arrow, the flat surface being guided by the slope of the V-shaped guide surface 9a, and the yarn end gripping guide 10 also being lowered. As a result of crossing the tip of the rapier 11 without crushing the form, the rapier 11 is hooked on the claws 11a of the rapier 11 described later.

Normally, the weft _Twf is kept on standby by the yarn end gripping guide 10 and the yarn feed guide having the guide hole so that the weft _Twf crosses the rapier 11 diagonally. When reaching the yarn feeding position, both guides are lowered to hook the weft yarn _Twf on the claws 11a of the rapier 11.

[0068] However, the use of feed yarn guide during feeding yarn to the rapier 11, when the weft T _wf is flat yarn, the guide hole weft T _wf will collapse squamous form rubbed in. For this reason, in the manufacturing apparatus for manufacturing the flat yarn woven fabric of the present invention, the pressing plate guide 9 is provided between the leaf spring tensioning device 8 and the yarn end gripping guide 10, and the yarn end gripping guide 10 is supplied when the yarn is supplied to the rapier 11. Is lowered, and the push plate guide 9 is advanced, so that the weft thread _Twf is pushed rearward of the loom and crosses the rapier 11.

The rapier 11 is, as shown in FIG.
This is a longitudinal member placed at the front of the reed 24
To operate in the horizontal direction, and the weft T_wfThe weaving department of warp yarn
T_wr, T _wrIt is inserted between them. Rapier 11
As shown in FIG. 2, a flat weft T _wfHook 11
a is provided at the tip, and a holding tool 11b is provided near the claw 11a.
Is installed.

As a method of gripping the flat weft thread _Twf with the rapier 11, as shown in FIG. 5, the end of the weft thread _Twf guided to the tip of the rapier 11 is gripped by the gripper 12. Thereby, weft insertion can be achieved without almost crushing the flat state.

In the manufacturing apparatus for manufacturing a flat yarn woven fabric according to the present invention, the weft _Twf wound around the bobbin 1 is fed by the take-up roller 3 at a constant speed in the weft supply step of the weft supply device as described above. The tension is released by the spring 4 b of the tension device 4 when the rapier 11 is unwound and intermittent weft thread is intermittently inserted. Then, the weft T _wf unwound from the bobbin 1, while being guided by the guide rollers 5-7, while being held in uniform tension leaf spring tension device 8, a pushing plate guide 9 and the yarn end gripping guide 10 Is hooked on the claws 11a of the rapier 11 and inserted between the warp yarns T _wr , T _wr of the weaving section as shown in FIG.

For this reason, the weft _Twf made of flat yarn is
It is woven without being twisted or flattened.

Next, the warp yarn supplying device will be described. The creel 20 has a number of bobbins rotatably supported, and FIG. 1 shows only the bobbins 20a and 20b. The bobbins 20a and 20b are provided with the warp T _{wr made of} flat yarn similarly to the bobbin 1 of the weft supply device.
Is wound, and the warp yarn _Twr is guided to the loom side by unwinding. Unwinding speed of the warp T _wr from the bobbin 12 is extremely slow compared to the weft T _wf, is constant speed, the bobbin 20a, 20b is no problem as long as with light brake.

The comb 21 is provided with support frames 2 arranged vertically.
A plurality of wires 21b provided in the vertical direction at the same interval as the warp _Twr of the fabric between 1a and 21a are connected, and the warp _Twr between the wires 21b and 21b.
Are passed one by one to determine the horizontal position. Here, the wire 21b is connected to the bobbin 20a of the creel 20,
Flat warps T _wr supplied from 20b the support frame 21
The length of the warp _Twr needs to be a predetermined length such that the flat surface of the warp _Twr contacts only the wire 21b without contacting the wires 21a and 21a. If the length of the wire 21b is less than the predetermined length, the warp _Twr will be crushed. The optimum length of the wire 21b is determined by the height of the creel 20 and the comb 2
1 and a distance to the horizontal guide 22, but a length of about 300 mm is required.

The horizontal guide 22 includes two guide bars 22
a, 22a, the warp yarns T _wr , T _wr unwound from the bobbins 20a, 20b are wound in an S-shape to regulate the vertical position. Here, the warp T _wr is comb 21 to be a flat surface is necessary to twist 90 degrees between the horizontal guide 22. For this reason, the interval between the comb 21 and the horizontal guide 22 depends on the width of the warp yarn _Twr , but needs to be separated by 50 mm or more. The interval between the comb 21 and the horizontal guide 22 is
If it is less than 50 mm, the warp yarn _Twr will pass through the horizontal guide 22 while being twisted and will be woven.

The healds 23 are arranged one by one for each warp yarn T _wr , and guide the warp yarns T _wr whose vertical position is positioned by the horizontal guide 22 to the reed 24. It is, make the shed through the weft T _wf to the downstream side of the reed 24 of each warp T _wr. Here, in the conventional heald, the mail has a vertically long shape in order to reduce interference between an adjacent thread and the heald. However, when a flat yarn is passed through a vertically long mail like this,
The flat shape is crushed, and weaving cannot be performed with the flat shape. Therefore, the heald 23
Is preferably formed in a horizontally long shape, and the mail 23a
Is set to be equal to or slightly longer than the width of the flat yarn used as the warp yarn _Twr . The shape of the mail 23a is preferably a rectangle or a horizontally long ellipse.

The reed 24 has a plurality of warp yarns T _wr unwound from a plurality of bobbins 20a, 20b and the like provided on the creel 20.
Are arranged at a predetermined density and guided to the cloth fell, and a large number of reeds 24b are vertically arranged on a frame 24a. Here, it is desirable to set the tension of the warp yarn _Twr as low as possible. This also in contact with the dents 24b lateral position slightly offset reed 24 the warp T _wr coming guided by the heald 23, is the tension of the warp T _wr is the flat shape is crushed low No, heddle 23
It is misaligned the warps T _wr shaking, because there is never warps T _wr are flat shape is crushed by one side of the mail 23a.

In the above-described warp yarn supplying device, the warp yarn _Twr is guided to the weaving cloth according to the following steps, and is woven into the weft yarn _Twf sent from the weft yarn supplying device to produce a flat yarn woven fabric.

First, a plurality of warp threads _Twr are unwound from a plurality of bobbins 20a, 20b and the like provided on the creel 20.

After the horizontal position of each warp yarn _Twr is determined by the comb 21, the warp yarn _Twr is twisted by 90 ° and guided to the horizontal guide 22.

Each warp T guided to the horizontal guide 22
After the position of the _wr is determined in the vertical direction, the _wr is guided by the heald 23 and is moved up and down by driving means (not shown) to
4 forms a shed through which the weft thread _Twf passes.

The plurality of warps T unwound from the plurality of bobbins 20a, 20b of the creel 20 in this manner.
_{The wr} is arranged at a predetermined density by the reed 24 and guided to the cloth fell.

When the shed is formed by the healds 23, a large number of warp threads T
_The weft thread _Twf is inserted between the _wr and the flat yarn woven fabric is manufactured as shown in FIG.

In the warp yarn supplying step, each warp yarn T _{wr is provided.}
Are arranged in a sheet shape at equal intervals, and stable weaving becomes possible.

Next, an example of a flat yarn woven fabric woven using the above-described manufacturing apparatus based on the above-described manufacturing method will be described below.

Example 1 Tensile breaking strength was 500 kg · f / mm ² and tensile modulus was 23,50.
It is made of carbon fiber yarn (Toray's T700 SC-12K (fineness: 7,200 denier) manufactured by Toray Industries, Inc.) with 0 kg · f / mm ² and elongation at break of 2.1%, with a yarn width of 6.5 mm and a yarn thickness of 6.5 mm. 0.10mm, flat width with a yarn width / yarn thickness ratio of 65, using a flat yarn with no twist, to which 1% of a sizing agent is applied to keep the shape,
A plain weave having a warp and weft density of 1.25 yarn / cm, a basis weight of 200 g / m ² , a fabric thickness of 0.22 mm, and a fiber density of 0.91 g / cm ³ was woven.

The obtained flat yarn woven fabric had a uniform fiber density with almost no voids at the intersection of the warp and the weft. The weaving speed was determined by using a similar carbon fiber yarn (Traya T300 B-3K, manufactured by Toray Industries, Inc., with a fineness of 1,800 denier), and the density of the warp and weft yarns was 5.0 yarns / c.
With a plain weave structure of m, the productivity was greatly improved at a speed as fast as 4 times that of a conventional flat yarn fabric having a basis weight of 200 g / m ² .

Next, the obtained woven fabric was impregnated with an epoxy resin, and four of the woven fabrics were laminated in the same direction to prepare a cured plate by an autoclave molding method.
The tensile strength at break was evaluated based on the FRP tensile test method.

The results are shown in Table 1 together with the carbon fiber volume content and tensile modulus.

Comparative Example 1 For the purpose of comparison, a flat yarn woven fabric having a plain weave structure in which the warp and weft yarns had a density of 1.25 / cm was woven by the conventional weaving method using the flat yarn of Example 1. .

The obtained woven fabric has a very coarse weave, a basis weight of 200 g / m ² , a woven fabric thickness of 0.34 mm, and a fiber density of 0.6.
It was 0 g / cm ³ .

The woven fabric was impregnated with an epoxy resin in the same manner as in Example 1, and four of the woven fabrics were laminated in the same direction to prepare a cured plate by an autoclave molding method.

As a result, in the laminating step, the resin in the voids of the woven fabric was taken off by the release film and chipped, and the resin had to be added accordingly. In addition, the obtained cured plate has irregularities in which the surface of the fabric is hollowed out,
There were many voids.

Further, the cured plate was evaluated for tensile breaking strength by the test method of Example 1, and the results are shown in Table 1 together with the volume fraction of carbon fiber and the tensile modulus.

[0095]

[Table 1]

As is evident from the results shown in Table 1, the cured board made from the flat yarn woven fabric of the present invention has a very high tensile strength at break, and the tensile elastic modulus is lower than that of the conventional carbon fiber woven fabric substrate. It shows an unexpectedly high value.

Further, as is apparent from the results of Comparative Example 1, a woven fabric having a fiber density as small as 0.60 g / cm ³ was obtained.
Even if an attempt is made to produce a cured plate having a high volume content of carbon fibers, the cured plate will have low strength due to poor resin impregnation. In this case, it is conceivable to increase the amount of resin used to enhance the resin impregnating property. However, in this case, a cured plate having a low volume content of carbon fibers is obtained.

Example 2 The same flat yarn woven fabric as in Example 1 was woven, and an unsaturated polyester resin was hand laid up on the flat yarn woven fabric.
up), and four of these were laminated to produce a cured plate cured at room temperature.

The cured plate obtained had a high volumetric content of carbon fibers of 45% despite being hand lay-up molding, and was completely impregnated with resin and free from voids. . This is made possible by the fact that the woven flat yarn woven fabric has a high fiber density of 0.91 g / cm ³ .

The cured plate thus obtained was evaluated by the test method of Example 1. As shown in Table 2, the cured plate had a strength as high as that of the cured plate obtained by the autoclave molding method of Example 1. The result was obtained.

[0101]

[Table 2]

Comparative Example 2 Tensile breaking strength was 360 kg · f / mm ² and tensile modulus was 23,500.
kg · f / mm ² , carbon fiber yarn with a breaking elongation of 1.5% (Trayka T300 B-3K manufactured by Toray Industries, Inc. (fineness: 1,800 denier)
)) And the warp and weft yarn density is 5.0 yarns / cm
Was woven by a conventional weaving method.

The obtained carbon fiber yarn woven fabric has a basis weight of 200 g.
/ M ² , woven fabric thickness 0.27 mm, fiber density 0.74 g / cm ³
Met.

In the same manner as in Example 2, the woven fabric was impregnated with an unsaturated polyester resin by hand lay-up, and four sheets were laminated and cured at room temperature. The resulting cured plate has a carbon fiber volume content of 32.1%, a normal value,
The resin impregnation properties were also good.

This cured plate was evaluated by the test method of Example 1 and the results are shown in Table 2 together with the carbon fiber volume content and tensile modulus.

The cured plate of Comparative Example 2 had no problem in terms of resin impregnation, and only the carbon fiber yarn used was different from the cured plate of Example 2. However, as shown in Table 2,
Judging from the tensile strength utilization rate at which these carbon fiber yarns contributed to the strength of the cured plate, the tensile breaking strength was extremely lower than that of the cured plate of Example 2.

In the cured plate of Comparative Example 2, the fiber density of the carbon fiber yarn woven fabric used was 0.74 g / cm ³ , whereas in the flat yarn woven fabric used for the cured plate of Example 2, the fiber density was reduced. 0.91
g / cm ^3, and thus the volume content of carbon fibers in the cured plate is high, and the flat yarn woven fabric of Example 2 exhibits high strength characteristics because the crimp of the woven yarn is small.

Here, Examples 1 and 2 and Comparative Examples 1 and 2
, The horizontal axis represents tensile strain (%) and the vertical axis represents tensile breaking strength (kg · f / mm ² ), and a strength characteristic diagram relating to a strength-strain curve shown in FIG. 4 was drawn.

As is clear from FIG. 4, in the cured plate of Comparative Example 2, the rate of change in tensile elastic strength was reduced from a tensile strain of about 0.6%. This is because when the cured plate of Comparative Example 2 was observed, cracks occurred in the resin.
This is presumed to be due to the fact that the crimp of the used carbon fiber yarn was stretched and the impregnated resin could not support the carbon fiber yarn.

Therefore, when this hardened plate is used as a structural material, it is dangerous to use the tensile strength at break as a reference, and it is necessary to use a lower tensile strength at the base.

Here, the tensile strength utilization rate refers to the ratio of the measured tensile strength to the theoretical strength calculated from the strength of the carbon fiber.

[0112]

As is apparent from the above description, the flat yarn woven fabric of the present invention has a fineness of 3,000 to 20,000 denier, a yarn width of 4 to 16 mm, and a yarn width / yarn thickness ratio of 30 or more . Sa
Since the warp yarn and the weft yarn made of the flat carbon fiber yarn to which the sizing agent is attached have a pitch of 1.0 to 1.2 times the yarn width and a fiber density of 0.8 g / cm ³ or more, ,
There are almost no voids between the yarns, and the fabric is very uniform and dense. At this time, the carbon fiber flat yarn has an adhering amount of the sizing agent in the range of 0.5 to 2.5% by weight,
If the flat yarn woven fabric has a woven fabric weight in the range of 100 to 300 g / m ² and a woven fabric thickness in the range of 0.1 to 0.4 mm, the flat yarn woven fabric exhibits the above-mentioned effect more.

In particular, the flat yarn woven fabric of the present invention is woven with a low-density thick carbon fiber yarn at a low density, so that the productivity is high and the manufacturing cost is low. Further, since the flat yarn woven fabric of the present invention is coarsely woven with CF flat yarn, it is easily deformed by shearing, and can be uniformly formed along a mold having a complicated shape. In addition, the carbon fiber woven fabric uses a flat yarn made of a yarn having a small crimp and a high fineness because the flat yarn is woven at a coarse density, and the fiber density is 0.8 g / cm. Since it is as high as ³ or more, the voids are small, so that when CFRP is produced, the volume content of carbon fibers is increased, and excellent effects such as exhibiting extremely high strength properties are exhibited.

Further, since the flat yarn woven fabric of the present invention has a smooth surface, when the FRP is manufactured, the surface of the FRP becomes flat and the coating becomes easy. In particular, the warp yarn and the weft yarn composed of the carbon fiber flat yarn constituting the flat yarn woven fabric of the present invention,
Because it is not twisted or flattened,
When fabricating CFRP with this woven fabric, unevenness in the surface due to uneven thickness of the twisted portion, excessive resin in the void of the twisted portion, generation of voids, and stress concentration at the twisted portion are caused. A decrease in strength can be avoided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a manufacturing apparatus for weaving a flat yarn woven fabric of the present invention.

FIG. 2 is an enlarged view in which the tip of a rapier is enlarged.

FIG. 3 is an enlarged perspective view of a yarn end gripping guide.

FIG. 4 is a strength characteristic diagram relating to a strength-strain curve of a cured plate produced using the flat yarn woven fabric of the present invention.

FIG. 5 is a perspective view showing another mode in which the weft is gripped by the rapier.

[Explanation of symbols]

Reference Signs List 1 bobbin (for weft thread) 2 tension roller 3 take-up roller 4 tension device (elastic suspension mechanism) 4a guide 4b spring 5-7 guide roller 8 leaf spring tension device (tension applying mechanism) 9 push plate guide 10 thread end gripping guide 11 Rapier 20 creel 20a, 20b bobbin (for warp) 21 comb 22 horizontal guide 23 heald 23a mail 24 reed T _wf weft T _wr warp

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-281037 (JP, A) JP-A-58-191244 (JP, A) JP-A-63-315638 (JP, A) JP-A-62 276053 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D03D 15/00 D03D 1/00 D03D 15/12

Claims (6)

(57) [Claims] An unwinding yarn having a fineness of 3,000 to 20,000 denier, a yarn width of 4 to 16 mm, and a yarn width / yarn thickness ratio of 30 or more.
A warp yarn and a weft yarn composed of carbon fiber flat yarn to which a sizing agent is attached, having a pitch of 1.0 to 1.2 times the yarn width, and a fiber density of 0.8 g / cm ³ or more. A flat yarn woven fabric, characterized in that: 2. The flat yarn woven fabric according to claim 1, wherein the carbon fiber flat yarn has an adhesion amount of the sizing agent in a range of 0.5 to 2.5% by weight. 3. The fabric weight is in the range of 100 to 300 g / m ² and the fabric thickness is in the range of 0.1 to 0.4 mm.
Or the flat yarn woven fabric according to 2. 4. The flat yarn woven fabric according to claim 1, wherein the warp yarn and the weft yarn have substantially no crimp. 5. A prepreg, wherein the flat yarn woven fabric according to claim 1 is impregnated with a synthetic resin in a range of 30 to 67% by weight. 6. A fiber reinforced plastic comprising the flat yarn woven fabric according to claim 1 and a matrix resin in a range of 30 to 67% by weight.