JP2002088640A - Air jet nozzle and method for enlarging yarn width of sheet with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air jet nozzle which jets air in a uniform jetting pressure in the longitudinal direction of the wide air jet nozzle, and to provide a method for enlarging the yarn width of a sheet, by which the thin sheet where the yarn widths of reinforcing fiber bundles are enlarging using the nozzle can be obtained. SOLUTION: This air jet nozzle comprising a nozzle plate in which a plurality of air-jetting holes are arranged at an equal pitch in one row, and nozzle cases, is characterized by extending an air-supplying pipe in the nozzle cases along the row of the arranged air-jetting holes, disposing a plurality of air-discharging holes in the air-supplying pipe in a row, and directing the air-discharging holes in the direction opposite to the nozzle plate side. The method for enlarging the yarn width of the sheet is characterized by jetting high pressure air on the surface of the sheet comprising reinforcing fiber yarns by the use of the air jet nozzle to enlarge the yarn width of the reinforcing fiber yarns of the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air jet nozzle for expanding a yarn width of a reinforcing fiber yarn by injecting high-pressure air to a sheet material made of a reinforcing fiber yarn, and a method of widening a yarn width of a sheet material using the same. It is.

[0002]

2. Description of the Related Art Carbon fiber composite materials in which carbon fibers are reinforced with resin have a high specific strength and specific elastic modulus, and have become established in aircraft materials, such as aircraft materials, which have great merits of weight reduction, and have recently been used in general industrial applications. The development is being actively studied.

In order to expand the carbon fiber composite material to general industrial applications, it is essential to reduce the cost of the carbon fiber. Recently, large-tow carbon fiber, which has a low carbon fiber production cost, has attracted attention. .

However, by arranging a plurality of large tow fiber bundles, a relatively thin sheet having a basis weight of about 150 to 400 g / m ^2, which has been used as a conventional reinforcing substrate of a carbon fiber composite material, will be obtained. Then, since there is a gap between the fiber bundles, there is a problem that the fiber density between the fiber bundle portion and the fiber bundle is greatly different, and there is a problem that a sheet material having non-uniform fiber dispersion is obtained. An important issue is to spread them evenly.

[0005] Although no proposal has been found for a method of making the fiber dispersion of a large tow sheet material uniform, for example, as disclosed in Japanese Patent Publication No. 2-33283, a water jet is applied to a reinforcing inorganic fiber woven fabric. Using a method of injecting water at high pressure to close the voids formed by interlacing of the warp and weft yarns can be considered to uniformly disperse the fiber bundle of large tow.However, due to the water jet, a drying step is required after the treatment. In addition, there is a problem that the surface treatment agent such as a coupling agent falls off due to the water jet, so that the treatment agent must be applied again after drying.

On the other hand, we have disclosed in Japanese Patent Application Laid-Open No. Hei 7-300739 a high-pressure air jet from an air jet nozzle in which a plurality of air jet holes are arranged in a row in a weft direction of a woven fabric made of a reinforced multifilament yarn having a limited bundle property of a fiber bundle. Is proposed to open and widen the weft yarn of the woven fabric by spraying.

In this method, the force for expanding the fiber bundle is small as compared with the water jet injection, but the yarn width can be sufficiently expanded by selecting a yarn having excellent spreadability. It is not necessary to pass through a drying step, and there is no fear that the coupling agent may fall off, so that a reinforcing fabric having a uniform fiber density can be easily obtained.

[0008] The weft of the woven fabric is opened by air jet.
In the case of widening, the spreading effect is smaller than that of a water jet, so that there is a problem that if the pressures jetted from the individual air jet nozzles are not made uniform, the spreading and widening unevenness may occur.

For example, if the supply port to the air nozzle case is at the center in the fabric width direction, the injection pressure from the injection hole near the center is high, and the injection pressure at the end in the fabric width direction is low. There is a problem that the opened state and the widened state are different between the center part and the end part.

As a means for solving the above problem, if the air supply amount is increased so that the air supply amount is larger than the total discharge amount from the air injection holes, the problem is somewhat improved, but the problem is that the air is wasted. There is a point.

When a thin sheet material is to be obtained from large tow carbon fibers, the arrangement pitch of the fiber bundles becomes very large. Therefore, even if the warp yarns and the weft yarns intersect like a woven fabric, the binding force is extremely high. Since it is weak, if the fiber bundle itself has an opening property, it can be easily opened by the air jet,
Although it is possible to increase the width, there is a problem that the jet pressure becomes non-uniform in the length direction of the nozzle, and unevenness occurs in the way the yarn width expands.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide an air jet nozzle having a uniform air jet pressure in the longitudinal direction of a wide air jet nozzle. It is still another object of the present invention to provide a method for widening the yarn width of a sheet material, which can obtain a thin sheet material in which the yarn width of the reinforcing fiber bundle is uniformly widened using such a nozzle.

[0013]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the air jet nozzle of the present invention, a nozzle plate in which a plurality of air injection holes are arranged in a line at an equal pitch,
An air jet nozzle comprising a nozzle case,
In the nozzle case, an air supply pipe is extended along the arrangement direction of the air injection holes, and a plurality of air discharge holes are provided in a row in the air supply pipe, and
The direction of the discharge hole is in the opposite direction to the mounting side of the nozzle plate, and the method for widening the yarn width of the sheet material of the present invention uses the air jet nozzle for reinforcement. The present invention is characterized in that high-pressure air is jetted onto the surface of a sheet material made of a fiber yarn to increase the width of the reinforcing fiber yarn of the sheet material.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings, which are one embodiment thereof.

FIG. 1 is a perspective view showing an example of an air jet nozzle according to the present invention, in which the inside is shown in a partially broken form, and FIG. 2 is a sectional view of the nozzle. It is a thing.

1 and 2, an air jet nozzle 1
Has a space formed by the nozzle cases 6a and 6b and the nozzle plate 2, and an air supply pipe 4 extends in the space in the direction in which the injection holes 3 are arranged.

In the nozzle plate 2, a plurality of air injection holes 3 are provided in a line at an equal pitch and are mounted on a nozzle case 6b.

The air injection hole 3 has a diameter of 0.1 to 1.0 m.
m, preferably 0.2 to 0.5 mm in diameter.

If the diameter of the air injection hole is smaller than 0.1 mm, the flow rate of the injected air is small, and the fiber bundle cannot be sufficiently expanded. On the other hand, if the diameter of the air injection hole is larger than 0.5 mm, the flow rate per injection hole is large, so that it is necessary to make the pitch extremely large in consideration of the balance with the supply amount. However, there is a problem that air cannot be finely sprayed to the ink and the ink tends to spread.

Air nozzle plate 2, nozzle cases 6a, 6b
In order to prevent air leakage, each is integrated by screwing with an O-ring sandwiched between the respective mating surfaces.

In the air jet nozzle 1, it is preferable to use the air jet holes 3 of the nozzle in alignment with the orientation direction of the reinforcing fiber yarns, for example, to increase the yarn width of the reinforcing fiber yarns. In doing so, it is preferable that the injection hole is provided at a position slightly longer than the yarn length in which the target reinforcing fiber yarns are arranged.

The air supply pipe 4 extends in the direction in which the air injection holes are arranged.
Is extended to the same length as the length provided,
In the air supply pipe, a plurality of air discharge holes 5 are provided in a line at an equal pitch, and it is important that the position of the air discharge holes 5 is provided in a direction opposite to the nozzle plate 2. It is.

The supplied high-pressure air passes through the air supply pipe 4 and is supplied with the air dispersed from the plurality of air discharge holes 5, so that the air is uniformly distributed in the arrangement direction of the injection holes 3. As a result, the air jet pressure in the direction in which the jet holes 3 are arranged becomes non-uniform.

Further, since the discharge hole 5 of the air supply pipe 4 is provided on the side opposite to the nozzle plate 2, the air discharged from the discharge hole 5 once faces the inner wall of the nozzle case 6a and is reflected by the inner wall. The air is then diffused toward the air injection holes 3, so that air with a more uniform pressure can be supplied to each air injection hole 3.

The discharge hole 5 provided in the air supply pipe 4 preferably has a hole diameter of about 0.5 to 5 mm and a pitch of preferably about 5 to 40 mm, and more preferably a hole diameter of about 2 to 3 mm. And those having a pitch of 10 to 20 mm are used.

The direction of the discharge hole 5 is preferably opposite to the direction of the nozzle plate 2.
The effect of diffusing air can be obtained even if the line connecting the center of the air injection hole 3 and the air blowing direction from the discharge hole 5 deviates by at least about ± 45 °. It is included in. Further, the arrangement of the air discharge holes 5 is preferably provided in a line at an equal pitch, but may be staggered at an equal pitch.

The cross-sectional shape of the air supply pipe 4 is not particularly limited, but a pipe having a circular cross section having a diameter of preferably about 20 to 40 mm can be used. By using a circular pipe, the air supply port 9 having a circular cross section for connecting to a hose having a circular cross section can be formed integrally with the hose, which is simple and preferable.

Between the air supply pipe 4 and the nozzle plate 2,
A rectifying plate including a metal mesh 7 and a perforated plate 8 is provided.

The air flow can be made uniform by the air passing through the respective gaps by the straightening plate, and the air can be supplied to the air injection holes 3 at a uniform pressure. In addition, by the mesh of the current plate,
This has the effect of preventing the passage of foreign matter and preventing the air injection holes 3 from being clogged.

As the metal mesh 7, a single stainless steel mesh # 70 to # 200 may be used. However, it is preferable to use several different meshes so that a further rectifying effect and a filter effect are exhibited. It is.

The perforated plate 8 is a plate made of a stainless steel plate having holes of about 3 to 6 mm in diameter of 5 to 1 / cm 2 and supports a metal mesh.

Next, a description will be given of a yarn spreading method for a sheet material made of reinforcing fiber yarns using the air jet nozzle of the present invention.

FIG. 3 is a perspective view for explaining a method for expanding the weft yarn width of the reinforcing fiber woven fabric with the air jet nozzle of the present invention. FIG. 4 is a perspective view showing the yarn width of the unidirectional sheet constituting the multiaxial stitch base material. FIG. 9 is a top view for explaining a method of expanding the width of the slab.

First, the reinforcing fiber fabric will be described with reference to FIG.

Reinforcing fiber woven fabric 1 woven from a loom
0 so that the air jet of the air jet nozzle 1 is jetted to the reinforcing fiber woven fabric from below, and is arranged so as to coincide with the arrangement direction of the air jet holes and the extending direction of the weft 11 of the reinforcing fiber woven fabric, and is sequentially woven. By injecting air into the incoming reinforcing fiber fabric, the reinforcing fibers constituting the weft are sequentially moved so as to be separated back and forth with respect to the traveling direction of the fabric at the air jetting position, so that the original fabric weft is A reinforcing fiber woven fabric having a wide yarn width and no gap between weft yarns can be obtained.

In the case of a woven fabric, when receiving the air jet, each reinforcing fiber constituting the weft yarn is interlaced with the warp yarn, so that it does not escape in the thickness direction of the woven fabric, and the weft yarn moves along the warp yarn. It expands in width.

Since the air jetted from the air jet nozzle 1 is diffused as the distance from the nozzle hole increases, it is preferable that the air jet nozzle 1 be as close as possible to the fabric surface. Is preferably about 1 to 5 mm.

If the distance is less than 1 mm, there is a problem that the woven fabric comes into contact with the nozzle surface and the weft is displaced. If the distance is more than 5 mm, the weft yarn is intensively opened because the air is diffused. There is a problem that the width cannot be increased, and it is difficult to uniformly increase the yarn width.

Although the warp yarn is tensioned on the woven fabric, the woven fabric may be lifted by jetting air to the woven fabric.
Is preferably provided. By doing so, the nozzle plate surface and the fabric surface can be held at a constant interval, and uniform yarn spreading can be performed.

Since the pressing plate and the woven fabric come into contact with each other, it is preferable to reduce the frictional resistance by attaching a Teflon coating tape or the like to the side of the woven fabric of the pressing plate 13.

Although the yarn width can be increased in principle by the air jet as described above, it is greatly affected by the opening property of the woven yarn itself constituting the reinforcing fiber woven fabric and the restrained state of the warp and weft yarns. It is.

With respect to the openability, the reinforcing fibers are preferably carbon fibers, glass fibers, polyaramid fibers, etc., preferably having a small amount of sizing agent (bundling agent) attached to the fiber bundle. Is a carbon fiber yarn, the sizing agent adhesion amount is preferably about 0.2 to 0.8% by weight.

The smaller the sizing agent is, the more excellent the spreadability is. However, if the sizing adhesion amount is less than 0.2% by weight, there is a problem that fluff is generated during the formation of the sheet material, and the adhesion amount is 0.2% by weight or more. When the amount is more than 0.8% by weight, the fibers are firmly adhered to each other, so that there is a problem that the spreadability is inferior and the yarn width is hardly spread by an air jet.

With respect to the restrained state of the warp and the weft, it is possible to reduce the restraint by forming a low-weight woven fabric with a reinforcing fiber yarn having a large fineness.

In the case where the reinforcing fiber is a carbon fiber woven fabric, the relationship between the fineness (D) of the carbon fiber yarn and the fabric weight (W) preferably falls within the range of the following formula.

W ≦ 7 × D ^{1/2 where} W is the fabric weight (g / m ² ) D is the fineness (dtex) of the carbon fiber yarn The relationship between the fineness (D) of the carbon fiber yarn and the fabric weight (W) is W
When ≧ 7 × D ^1/2 , the warp yarn and the weft yarn are strongly restrained, and the woven yarns are crimped greatly to each other. The width cannot be expanded.

Further, in order to satisfy the above equation, the fineness of the carbon fiber yarn is 3.500 to 200,000 dtex.
In the range, the weight of the fabric is preferably 100 to 600 g / m ² , more preferably 100 to 300 g / m ² , and the effect of the present invention is preferably exhibited.

A carbon fiber yarn having a fineness of 3,500 dtex or less becomes an expensive woven fabric base due to the high production cost of the yarn.
It cannot be developed for general industrial use. On the other hand, when the fineness is 200,000 dtex or more, the cost of producing the yarn is reduced, and the base material becomes inexpensive.
Fabric weight 15 commonly used for the above carbon fiber yarns
When trying to obtain a woven fabric of 0 to 400 g / m ² , there is a problem that it is difficult to spread uniformly because the yarn spacing is too large. In the present invention, the fineness of the carbon fiber yarn is 3,50.
The effect is exhibited in the range of 0 to 200,000 dtex.

In the above method, the air pressure supplied to the air jet nozzle varies depending on the type of fabric and the passing speed of the fabric, but is preferably 0.3 to 0.7 M
It is sufficient if the pressure is in the range of Pa. Even if the pressure is less than 0.3 MPa, the yarn width is widened, but the unevenness of the yarn width is likely to occur, and the pressure is higher than 0.7 MPa. Even if it is raised, the yarn spreading effect does not change and is wasted.

The yarn may be spread during weaving by mounting an air jet nozzle on the loom, but may be performed in another process after weaving.

When the operation is performed during weaving, if the operation of the loom and the air supply to the air jet are linked, the air jet will not be disengaged while the loom is stopped, so that a side step does not occur. .

FIG. 3 shows an example in which an air jet nozzle is provided below the fabric and air is jetted upward.
An air jet nozzle may be provided on the upper side of the fabric and air may be jetted downward.

Although the description has been given of the expansion of the weft yarn width of the woven fabric by the air jet, it is difficult to expand the warp yarn width by the air jet of the present invention. Therefore, the present invention is combined with the yarn expansion technology by another means.

Next, a method for expanding the yarn width of the unidirectional sheet material constituting the multiaxial stitch base material will be described with reference to FIG.

FIG. 4 shows a stitch m in which a plurality of sheet materials in which reinforcing fiber yarns are arranged in one direction are laminated at an angle and integrated by stitches to form a multiaxial stitch base material.
/ C shows a part of the sheet material forming part, and the endless chains provided on the left and right of m / c to supply the reinforcing fiber yarn in a state where the unidirectional sheet material is laminated before stitching. A unidirectional sheet is formed while a plurality of reinforcing fibers are hooked on the pins 14a and 14b. FIG. 4 shows a case where a unidirectional sheet material 16 oriented at -45 ° is formed, and the next layer is formed from above. Is +45.
The position at which the sheet material 15 oriented in degrees is formed is shown.

Immediately after the reinforcing fiber yarn is oriented at + 45 °, the air jet nozzle 1 is provided so as to coincide with the direction in which the reinforcing fiber extends, and the air jet nozzle 1 is oriented according to the same principle as the method for expanding the weft yarn width of the woven fabric described above. In this case, the width of the reinforcing fiber yarn is increased to form a sheet having a uniform fiber density.

In this case, unlike the woven fabric, the warp and the weft do not intersect, so that the opening of the fiber bundle by the intersect is not hindered, and there is no restriction on the relationship between the fineness of the reinforcing fiber yarn and the basis weight of the sheet. . Therefore, if the opening property of the reinforcing fiber yarn itself is excellent, it is possible to easily increase the yarn width of the reinforcing fiber yarn.

The present invention is characterized in that a thin and uniform sheet is obtained with a reinforcing fiber yarn having a large fineness.
In that sense, the fineness of the reinforcing fiber yarn is in the range of 3,500 to 200,000 dtex, more preferably 5,000 to 200,000 dtex, for the same reason as the woven material.
Is a thick fiber yarn having a basis weight of preferably 100 to 600 g /
By forming a sheet material of m ² , more preferably 100 to 300 g / m ² , the effect of the present invention can be advantageously exhibited. In particular, when the reinforcing fiber is a carbon fiber yarn, the yarn value is expensive, and the carbon fiber yarn having a small fineness is more expensive. Obtaining a sheet material having uniform uniformity is a great effect in terms of cost.

Regarding the opening property of the reinforcing fiber yarn, the amount of the sizing material attached is related similarly to the above-mentioned woven material, and the preferred amount of attachment is 0.2 to 0.8% by weight.

Further, since the reinforcing fiber yarn is not restrained by the warp yarn, when the high-pressure air is jetted, the reinforcing fiber yarn may turn and converge in reverse, and the width of the yarn becomes unstable. A porous net or a thin piano wire is attached to the comb-like wing from the point where air is injected with the directional sheet material, and the reinforcement fiber yarn is prevented from turning by holding the reinforcement fiber yarn lightly with the piano wire. This is preferred.

In this case, since the sheet material moves while being held down by the porous net or the like, it is necessary that the surface of the porous net contacting the reinforcing fiber sheet material should not be caught.

[0062]

According to the present invention, it is possible to provide an excellent air jet nozzle capable of supplying air to each of the air injection holes with a uniform pressure, thereby uniformly spreading the reinforcing fiber yarn. This makes it possible to stably provide a reinforcing fiber base material that is thin with a thick reinforcing fiber yarn and has excellent fiber dispersion.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an air jet nozzle of the present invention.

FIG. 2 is a sectional view showing an example of the air jet nozzle of the present invention.

FIG. 3 is a perspective view showing an example of a method for expanding the weft yarn width of a reinforcing fiber woven fabric using the air jet nozzle of the present invention.

FIG. 4 is a top view showing an example of a method for increasing the yarn width of a reinforcing fiber yarn of a unidirectional sheet material constituting a multiaxial stitch base material using the air jet nozzle of the present invention.

[Explanation of symbols]

 1: air jet nozzle 2: nozzle plate 3: air injection hole 4: air supply pipe 5: air discharge hole 6a, 6b: nozzle case 7: metal mesh 8: perforated plate 9: air supply port 10: reinforcing fiber fabric 11: Weft yarn 12: warp yarn 13: holding plate 14a, 14b: yarn hooking chain 15: + 45 ° oriented unidirectional sheet 16: -45 ° oriented unidirectional sheet

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3B154 AA14 AB20 AB27 BA45 BB35 BB45 BC08 BE01 BF07 BF11 BF16 DA30 4F033 AA00 BA02 CA04 DA01 EA06 JA04 NA01

Claims (9)

[Claims] 1. An air jet nozzle comprising a nozzle plate in which a plurality of air injection holes are arranged in a line at an equal pitch, and a nozzle case, wherein the air injection nozzle is provided in the nozzle case along a direction in which the air injection holes are arranged. The air supply pipe is extended, a plurality of air discharge holes are provided in a row in the air supply pipe, and the direction of the discharge holes is in a direction opposite to a mounting side of the nozzle plate. An air jet nozzle characterized by the following. 2. The air jet nozzle according to claim 1, wherein said air discharge holes are arranged at an equal pitch. 3. The air jet nozzle according to claim 1, wherein a flow straightening plate made of a perforated plate and a metal mesh is provided between the air supply pipe and the nozzle plate. 4. High-pressure air is jetted onto the surface of a sheet material made of reinforcing fiber yarns using the air jet nozzle according to any one of claims 1 to 3, whereby the reinforcing fiber yarns of the sheet material are formed. A method for widening a yarn width of a sheet material, characterized by expanding a width. 5. An orientation direction of a reinforcing fiber yarn of said sheet material,
5. The method according to claim 4, wherein the air jet nozzles are arranged in a direction in which air injection holes are arranged. 6. The method according to claim 4, wherein the sheet is a reinforcing fiber woven fabric comprising a warp and a weft. 7. The sheet material is a uniaxial sheet material having at least 90 ° orientation or a multiaxial stitch base material including a unidirectional sheet material oriented in a range of ± 30 to ± 60 °. The method for widening the yarn width of a sheet material according to claim 4 or 5. 8. The reinforcing fiber yarn having a fineness of 3,500 to 2,
The method according to any one of claims 4 to 7, wherein the carbon fibers are in the range of 000 dtex. 9. One of the sheet materials weighs 100 to 600 g.
9. The method according to claim 4, wherein the sheet material has a basis weight in the range of / m ² .