JP2000335932A - Nozzle tip for spinning flat glass fiber and apparatus for production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nozzle tip capable of stably spinning glass fibers having a highly flat cross section in >=2.0 flatness ratio and raising the arrangement density of nozzle holes. SOLUTION: This nozzle tip 13 is capable of raising the arrangement density by adjacently arranging a pair of nozzle holes 24 and 24 having a flat cross-sectional shape parallel in the nozzle tip 13 provided on the undersurface of a nozzle plate 12, further forming recessed notched parts 25 on the nozzle hole wall in the nozzle hole wall in a region sandwiched between the nozzle holes 24 and 24, rapidly cooling a molten glass flowing down from the nozzle holes 24 and 24 with the notched parts 25 and thereby suppressing a phenomenon of rounding the withdrawn molten glass. As a result, the production of glass fibers having a flatness ratio nearly equal to that of the nozzle holes 24 and 24 can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle tip used for producing flat glass fibers having a deformed cross section having a high aspect ratio and an apparatus for producing flat glass fibers.

[0002]

2. Description of the Related Art Conventionally, FIGS.
Flat glass fibers 1 having a flat cross section as shown in (c) have been developed. In particular, a flat glass fiber having a cross section of a shape close to a rectangle with a ratio of the major axis to the minor axis (hereinafter, referred to as the oblate ratio) of 2 or more. Glass fiber increases the strength of the resin product containing the fiber, increases the smoothness of the surface, reduces warpage and torsion, increases the vibration damping effect. Since the packing density can be increased, it can be used as a substitute for glass cloth. In this specification, the major axis and the minor axis of the flat cross section are defined as a rectangle 2 circumscribing the cross section of the flat glass fiber 1 as shown in FIG. A length A (corresponding to the longest dimension of the fiber cross section) and a short side length B (corresponding to the longest dimension in a direction substantially perpendicular to the major axis of the fiber cross section) are shown, and therefore, the aspect ratio is A / B. This aspect ratio is also applied to a cross-sectional shape of a nozzle hole described later.

In general, glass fibers are discharged from a nozzle plate having a large number of nozzle chips formed from molten glass.
It is manufactured by cooling and solidifying while being stretched. In the conventional method of manufacturing flat glass fibers, for example, a nozzle tip having a nozzle hole having a flat cross section as shown in JP-A-1-266937 is used. Except as described above, it is manufactured in a similar manner. However, even if such a nozzle tip is used, it is extremely difficult to efficiently obtain desirable flat glass fibers because the discharged molten glass tends to be rounded due to surface tension. That is, in order to suppress the molten glass discharged from the nozzle tip from being rounded, it is necessary to lengthen or thin the nozzle tip so that the glass temperature at the time of discharging from the nozzle tip becomes low. In this case, the resistance due to the nozzle holes increases, so the amount of molten glass discharged decreases, and the spinning speed must be reduced.Furthermore, the temperature of the molten glass at the nozzle tip outlet decreases, resulting in insufficient fluidity. In addition, even if the discharge temperature from the nozzle tip is lowered, there is still a tendency that the molten glass discharged tends to become round even if the discharge temperature from the nozzle tip is lowered. It becomes much smaller than the flatness ratio of the hole cross section, and eventually flat glass fibers having a high flatness ratio of 2 or more, for example, 150 It was virtually impossible to produce by high speed spinning such m / min or more. In particular, glass fibers having good acid resistance called ECR glass have a large surface tension, and thus have been particularly difficult to produce.

Accordingly, nozzle tips capable of efficiently spinning flat glass fibers have been developed. For example, JP-A-6-228806, JP-A-7-123603, and JP-A-7-133132 have been developed. Has been proposed. These publications disclose a technique relating to a nozzle tip having a cross section of a rectangular hole, and an orifice provided with protrusions on both sides of a short side of the rectangular hole. However,
Even with a bushing plate provided with a large number of holes of these shapes, it was difficult to stably produce a large amount of flat glass fibers.

Japanese Patent Application Laid-Open No. 11-43343 has a nozzle hole whose cross section is oblong or similar to an ellipse, and the cross-sectional area of the nozzle hole is changed from the inlet side of the molten glass to the outlet side. There has been proposed a nozzle tip that is gradually reduced in size. With this nozzle tip, it is possible to reduce the turbulence of the flow of glass in the nozzle tip and increase the cooling effect, and it is possible to produce flat glass fibers having a high aspect ratio with high productivity compared to conventional nozzle tips. It has the advantages that it can. However, even with this nozzle tip, there is still a considerable tendency for the molten glass discharged from the nozzle tip to be rounded.For example, the flatness ratio of the obtained glass fiber is about half the flatness ratio at the discharge port of the nozzle hole. There is a problem that it is difficult to produce flat glass fibers having a large flattening ratio. When a large number of nozzle tips are mounted on the nozzle plate, an appropriate spacing is required between the nozzle tips on the work. Therefore, the number of arranged nozzle tips per unit area of the nozzle plate, that is, the number of arranged nozzle holes is reduced. There is also a problem that the area of the nozzle plate used for spinning a desired number of glass fibers becomes large, which is not so large.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is intended to reduce flat glass fibers having a high flat cross section having an oblate ratio of 2.0 or more to 15 times.
It is an object of the present invention to provide a nozzle tip which can be operated stably with almost no breakage while spinning at a high speed of not less than 00 m / min.

Further, the present invention can be provided in such a manner that the arrangement density of the nozzle holes with respect to the nozzle plate is increased, thereby making it possible to reduce the size of the nozzle plate. Another object is to provide a glass fiber manufacturing apparatus using chips.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a pair of flat cross-sectional nozzle holes are formed in the nozzle tip so that the major axis direction is parallel. Disposed in close proximity to the pair of nozzle holes, by providing a concave nozzle hole wall cutout on the nozzle hole wall in the area sandwiched between the pair of nozzle holes, despite the close proximity of the pair of nozzle holes. The molten glass discharged from the nozzle hole is cooled without almost reducing the aspect ratio and becomes glass fiber without causing the trouble that the molten glass merges, and therefore, the glass fiber having a high aspect ratio is reduced. The present inventors have found that spinning can be performed stably and completed the present invention. That is, the present invention is a flat glass fiber spinning nozzle tip including a nozzle portion and at least a pair of nozzle holes penetrating the nozzle portion, wherein the pair of nozzle holes have a flat cross-sectional shape and have a long diameter direction. Are arranged in parallel with each other, and the nozzle hole wall of the region sandwiched between the pair of nozzle holes is provided with a concave nozzle hole wall cutout portion, for flat glass fiber spinning. It is a nozzle tip.

As described above, in the nozzle tip of the present invention, of the two long sides of each nozzle hole having a flat cross section,
Since the cutout is formed by cutting out the nozzle hole wall on one long side, the molten glass flowing down the nozzle hole,
It flows down with the long side nozzle hole wall on the side where there is no notch in a wet state, so that it flows down while maintaining a flatness almost equal to the flatness ratio of the nozzle hole cross section. Because it is cooled from the tip of the nozzle tip, it is appropriately cooled at the time of discharge from the tip, the tendency to curl is reduced, and then, when fiberized while being stretched, the aspect ratio hardly decreases, In some cases, it may increase, resulting in flat glass fibers. In addition, when the molten glass flows down the notch of the nozzle hole, one side of the molten glass flowing down is opened, so that the flowing resistance is reduced, and the molten glass passing through the nozzle portion is cooled and the viscosity is lowered. Even if it becomes high, there is no problem, and the molten glass flows down stably. Therefore, a glass fiber having a desired aspect ratio can be obtained stably even when spun at a high speed.

Further, the notch formed in the wall of the nozzle hole is provided between the pair of nozzle holes arranged close to each other. Due to the difference in viscosity due to the difference in cooling speed based on the presence or absence, it curves to the side with the notch, sticks to each other, becomes large beads, falls quickly, and even if the molten glass joins, the two molten glass Since the temperature of the opposing surfaces is lowered by cooling by the cutouts, the molten glass can be immediately diverted by pulling the molten glass, and the normal spinning state can be promptly entered. Thus, the spinning start operation can be performed promptly. Also, despite the fact that the pair of nozzle holes are arranged close to each other, the two molten glasses hardly merge during the steady operation, and stable spinning can be performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to embodiments of the present invention shown in the drawings. FIG.
BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows the manufacturing apparatus of flat glass fiber by one Embodiment of this invention schematically, 11 is a glass melting furnace, 1
2 is a nozzle plate arranged on the bottom surface, 13 is a nozzle chip provided on the lower surface of the nozzle plate 12,
14 is a glass fiber spun from the nozzle tip 13;
5 is a cooling fin for cooling the nozzle tip 13 and the glass fiber 14, 16 is a water cooling unit for cooling the cooling fin 15, 17 is a sizing agent application device for applying a sizing agent to the glass fiber 14, 18 Is a collecting roller for collecting a large number of glass fibers, and 19 is a winder for winding the collected glass fibers. The glass fibers 14 spun from each nozzle tip 13 are collected by a collecting roller 18 and wound on the winder 19. ing. Here, nozzle tip 1
Reference numeral 3 denotes an embodiment of the present invention, which is provided with a nozzle hole having a flat cross-sectional shape as described later, thereby producing a glass fiber having a flat cross-section.

FIG. 2 is a schematic perspective view of the nozzle tip 13 (not shown inside the molten glass reservoir), and FIG.
4 is a schematic bottom view of the nozzle tip 13. A large number of nozzle tips 13 are provided on the lower surface of the nozzle plate 12. The nozzle tip 13 may be manufactured separately from the nozzle plate 12 and attached by welding or the like. Alternatively, the nozzle plate 13 may be formed by machining a single plate using a milling machine, an end mill, or the like, or performing electrical discharge machining, pressing, or the like. 12 may be made as an integral structure.

[0013] The nozzle tip 13 is provided with the nozzle plate 12.
A molten glass reservoir 22 for introducing molten glass above the nozzle, a nozzle 23 formed below the molten glass reservoir 22 and having a great effect on the cross-sectional shape of the flat glass fiber, and the nozzle 23 is provided through the nozzle 23. A pair of cross sections has a flat nozzle hole 24. In the present invention, the number of the nozzle holes 24 provided in the nozzle tip 13 is not limited to the pair shown in FIG. 4, but may be a plurality of pairs (three pairs in the drawing) as shown in FIG. Further, in the embodiment shown in FIG. 3, the outer shape of the nozzle portion 23 is the same as the outer shape of the region where the molten glass reservoir portion 22 is formed thereon. However, the present invention is not limited to this configuration. As shown, the nozzle portion 23 may have an outer shape smaller than the region where the molten glass reservoir portion 22 is formed thereon. When this configuration is adopted, the nozzle portion 23
This has the advantage that the cooling effect can be further enhanced.
In the illustrated embodiment, the outer shape of the nozzle tip 13 and the nozzle portion 23 formed therein is a rectangular parallelepiped, but is not limited thereto, and may be changed to a pyramid, a cylinder, a cone, or the like. However, if the illustrated rectangular parallelepiped is used, there is an advantage that processing when manufacturing a nozzle plate provided with a large number of nozzle tips from one sheet by machining is easy.

2 to 4, a pair of nozzle holes 24 formed in the nozzle portion 23 have a flat cross section. Here, the “cross section” means a cross section in a plane perpendicular to the direction of the molten glass flowing down in the nozzle hole 24. However, since a notch 25 is formed in a part of the nozzle hole wall surrounding the nozzle hole 24 from the tip side (lower surface side) as described later, the position of the notch 25 Since the cross-sectional shape of the nozzle hole 24 is different at a position where no nozzle is present, the “cross-section” in this specification is used.
Is a position where there is no notch 25 (that is, notch 2
5 (a position above 5).

Specific examples of the flat shape adopted as the cross-sectional shape of the nozzle hole 24 include a rectangle, a rectangle having four rounded corners, and a half of a diameter equal to the length of the short side at both ends in the longitudinal direction of the rectangle. Examples include a circle (oval), a rectangle with a partial circle with a diameter larger than the short side at both ends in the longitudinal direction (dumbbell shape), an ellipse, or a shape similar to these. The illustrated embodiment shows an oval shape. The cross-sectional shape and the aspect ratio of the nozzle hole 24 are as follows:
Although it is determined according to the cross-sectional shape and the flatness ratio of the flat glass fiber to be manufactured, when the nozzle tip of the present invention is used, the flatness ratio of the manufactured flat glass fiber is determined by the flatness ratio of the cross section of the nozzle hole. Since the values are relatively close, the aspect ratio of the nozzle hole 24 may be set to a value equal to or close to the aspect ratio of the flat glass fiber to be manufactured. For example,
When manufacturing flat glass fibers having an aspect ratio of 2.0 to 10, the aspect ratio of the nozzle hole 24 to be used may be set to about 2.0 to 10. Generally, the flattening ratio of the flat glass fiber is preferably 3.0 or more, so that the flattening ratio of the nozzle hole 24 is also preferably 3.0 or more. On the other hand, when the aspect ratio of the nozzle hole 24 is large, the cross-sectional shape of the fiber tends to be unstable, and efficient production is difficult. Therefore, the aspect ratio is preferably 10 or less, and further preferably 8.0 or less. Is more preferable. The shortest diameter of the nozzle hole 24 is adjusted to match the type and production amount of the molten glass, but is 0.5 mm or more, preferably 0.8 mm
It is desirable that this is the case. If it is less than 0.5 mm, the outflow of the molten glass is not smooth, and the fiber dimensional change is undesirably large.

The pair of nozzle holes 24, 24 are arranged in parallel in the major axis direction.
A nozzle hole wall cutout 25 that is concave from the tip end side of the nozzle tip is provided in the nozzle hole wall in the region sandwiched between the nozzle holes except for both ends of the nozzle hole. Therefore, the nozzle hole wall surrounding each nozzle hole 24 at the tip of the nozzle tip 13 has a long-diameter nozzle hole wall 24a forming the long-diameter nozzle hole wall of the nozzle hole 24 and a short-diameter nozzle hole wall at both ends. It is formed of a short-diameter nozzle hole wall 24b to be formed and a long-diameter end nozzle hole wall 24c that forms a part of the long-diameter nozzle hole wall on both sides of the nozzle hole wall cutout 25.

Thus, when the molten glass is discharged from the nozzle hole 24, when the molten glass passes through the cutout portion 25 of the nozzle hole wall, the area facing the cutout portion 25 is cooled and the surface tension is reduced. But the notch 25
In the region excluding, the high-temperature nozzle hole walls 24a, 24b,
Cooling is suppressed because it is surrounded by 24c, and the nozzle wall 24a, 24b, 24c wets and spreads and keeps a shape substantially equal to the cross-sectional shape of the nozzle hole 24 until it leaves the tip of the nozzle tip 13. Then, even after leaving the tip of the nozzle tip 13, the surface of the flat glass fiber facing the nozzle hole wall cutout portion 25 is cooled and the surface tension is reduced. When glass fibers are stretched at high speed, they hardly curl due to surface tension. Further, when the molten glass flows down the notch portion 25 of the nozzle hole 24, one side of the flowing molten glass is opened, so that the flowing resistance is reduced, and the molten glass passing through the nozzle portion 13 is cooled. Even if the viscosity increases, there is no problem, and the molten glass flows down stably. Thus, flat glass fibers having a flat ratio substantially equal to the flat ratio of the nozzle hole 24 can be stably manufactured at high speed.

As described above, the nozzle hole wall cutout 2
No. 5 has the effect of cooling one surface of the molten glass during discharge to reduce the surface tension and increase the flattening efficiency. The size of the cutout portion 25 of the nozzle hole wall is determined in consideration of various factors such as the glass melting temperature, the spinning speed of the glass fiber, and the stability of the aspect ratio so that this effect is more effectively exhibited. Specifically, the nozzle hole wall cutout 25
Are arranged so that the center thereof coincides with the center of the nozzle hole 24 in the long diameter direction, and the width W (the length in the direction perpendicular to the flowing direction of the molten glass) is usually the length L of the nozzle hole wall in the long diameter direction. Is set to 30% to 100%, preferably 40% to 90%, and most preferably 50% to 80%. If it is less than 30%, the effect of the cutout portion is small. On the other hand, if 100% of the nozzle hole wall in the long diameter direction is cutout and the short side portion (nozzle hole wall 24b) is reduced to 1/2 or less, supercooling will occur, When the glass passes through the cutout portion 25, the glass does not wet to the short side portion and starts to curl, and the flattening efficiency is deteriorated. The depth D (the length in the flowing direction of the molten glass) of the cutout portion 25 of the nozzle hole wall is related to the length C of the nozzle portion 23. is there. The length C of the nozzle portion 23 is set so as to secure a length capable of forming the cutout portion 25 and to appropriately cool the molten glass flowing down.
It is preferably set to about 1 to 6 mm, more preferably 1 to 4 mm. The depth D of the cutout portion 25 is determined by the effective length of the nozzle portion 23 [in this specification, the minimum thickness (usually 0. About 3mm)
It is preferably 10 to 100%, and more preferably 30 to 80%.

The pair of nozzle holes 24, 24 are arranged in parallel in the major axis direction, and the two nozzle holes 24 can be arranged in a smaller space. By forming the nozzle hole wall cutout portion 25 in a region sandwiched between the pair of nozzle holes 24, 24, the following operation and effect can be obtained. That is, as shown in FIG. 9, if the nozzle hole wall cutout portion 25 'is formed outside the pair of nozzle holes 24, 24, as shown in FIG. Begins to flow down from the nozzle holes 24, 24, the molten glass 28 coming out of the nozzle holes 24 rises to the side where the notch 25 'is formed due to the difference in viscosity due to the difference in cooling rate between the two surfaces, and the nozzle plate 12 The lower surface of the device may be soiled, or as shown in FIG.
When the molten glass 28 coming out of the nozzle holes 24, 24 sometimes merges, the molten glass 28 does not diverge because the temperature of the merging surface is high.
Even if air is blown, a problem arises in that the air does not easily diverge and hinders the spinning operation. However, as in the present invention, when a cutout portion 25 is provided between the pair of nozzle holes 24, 24, When the molten glass that has started to be discharged from the pair of nozzle holes at the start of spinning curves toward the side where the notch portion 25 is formed, the molten glass sticks to each other, becomes large beads, and falls quickly, thus contaminating the lower surface of the nozzle plate. No, and even if the discharged molten glass merges,
Since the facing surfaces of the two molten glasses have been cooled by the cutouts 25, the temperature has been reduced. Therefore, the molten glass from the pair of nozzle holes 24, 24 is immediately diverted by pulling, and even when not diverted. The air can be easily diverted by blowing the air, and the normal spinning state can be promptly entered. Thus, the spinning start operation can be performed promptly. Here, a pair of nozzle holes 24, 2
The interval of 4 (distance between the nozzle hole walls on the adjacent side) is preferably narrower from the viewpoint of compact arrangement of the nozzle holes,
If the width is too narrow, the molten glass will merge during operation. Specifically, about 1.1 to 2.0 times the minor diameter of the nozzle hole, or 1 to 2 mm
The degree is preferred.

In order to further stabilize the flattening of the glass fibers discharged from the nozzle hole 24, the width of the tip end of the nozzle hole 24 and the both ends in the major axis direction are not larger than the maximum width of the minor axis of the nozzle hole 24. Alternatively, a modification may be made such as providing a concave groove having a depth of about 0.1 to 0.7 mm or providing a convex edge having a height of about 0.1 to 0.7 mm.

As shown in FIG. 3, a molten glass reservoir 22 is provided above the nozzle hole 24 of the nozzle tip 13. The molten glass reservoir 22 is provided for stabilizing the flow of the molten glass to the nozzle hole 24, and may be omitted if not necessary. For example, as shown in FIG. 7, the nozzle plate 12 may be provided with a nozzle chip 13A having no molten glass reservoir, and the nozzle hole 24 may directly communicate with the upper surface of the nozzle plate 12.

In a nozzle tip having a glass reservoir at the upper part of a nozzle hole of a glass fiber spinning nozzle tip having a circular cross section, a columnar or conical reservoir is generally provided, as shown in FIGS. 3 and 4. So that a pair of flat nozzle holes 2
In the case where the molten glass reservoir 22 is provided on the top 4 or 24, the viscosity of the molten glass near the wall surface is increased by the cooling effect to improve the flattening efficiency, and the distribution of the outflow is reduced because the long diameter of the nozzle hole is long. In order to make it suitable for the cross-sectional shape of the flat glass fiber to be manufactured,
It is also preferable that the cross-sectional shape of 2 is an elongated shape similar to the cross-sectional shape of the pair of nozzle holes 24, 24. Further, by changing the cross-sectional shape of the molten glass reservoir 22 into an oval, an ellipse, a dumbbell, or the like, the cooling and flow of the glass in the nozzle tip can be controlled.

The cross-sectional area of the molten glass reservoir 22, that is, the area of the molten glass inflow portion, is set larger than the cross-sectional area of the opening of the pair of nozzle holes 24, 24, and is set so as not to hinder the installation of the adjacent nozzle tips. Specifically, it is desirably 3 to 16 times, preferably 4 to 10 times, the total area of the pair of nozzle holes 24, 24. At 3 times or less, there is little difference from a nozzle tip that is straight and has no glass pool. At 16 times or more, a dead zone is formed in the glass pool, high-viscosity molten glass is easily generated, spinning is stabilized, and the cross-sectional shape of flat glass fiber Not only does this have an adverse effect on stabilization, but also the cross-sectional area of the nozzle tip having a glass reservoir increases, the number of nozzle tips that can be arranged in the same area decreases, and the production amount of flat glass fibers decreases. The depth of the molten glass reservoir 22 is determined from the overall length of the nozzle tip 13 and the length of the nozzle hole 24 in consideration of the degree of cooling of the molten glass, turbulence of the flow, and the like. The depth is from 0 mm to twice the thickness of the nozzle plate, preferably 1-2 times. If the depth is small, the effect is small. If the depth is too small, the cooling is excessive, and the discharge amount of the molten glass from the nozzle tip is reduced, and the cross-sectional shape of the flat glass fiber tends to be unstable.

The cross-sectional shape of the molten glass reservoir 22 may be such that the shape of the inlet is straight down to just above the nozzle hole, or the inlet and the nozzle hole are connected by a smooth surface, and most of the steps are formed. It may have a tapered shape. The molten glass reservoir 22 is not limited to the case where the molten glass reservoir 22 is common to the pair of nozzle holes 24, and an independent molten glass reservoir may be provided corresponding to each nozzle hole 24.

As described above, the nozzle hole cutout portion 2 is provided between the pair of flat nozzle holes 24, 24.
5, the molten glass discharged in a flat state from the nozzle chip 13 is hardly rounded when it is stretched and fiberized, and is cooled and solidified while maintaining the flat state. As a result, it is possible to stably produce a high flat glass fiber having a flat ratio of 2 or more at a high speed. Conventionally, when manufacturing flat glass fiber, a method of blowing cold air to quickly cool and solidify the discharged molten glass in order to suppress the molten glass discharged from the flat nozzle hole from curling is adopted. However, in the nozzle tip 13 of the present invention, such cooling by cold air is not necessary, and the cooling itself can be omitted. However, in order to increase the spinning speed, it is necessary to perform cooling, but in this case, cooling spraying is not necessary, and the use of cooling fins used in the production of conventional glass fibers having a circular cross section is sufficient. A great cooling effect can be obtained. Therefore, in the embodiment shown in FIG. 1, a large number of cooling fins 15 are arranged below the nozzle plate 12, and by adopting this configuration, flat glass fibers can be stably manufactured. In the method of cooling by blowing cool air, the cooling rate varies greatly depending on the amount of cool air, so it is necessary to precisely control the amount of cool air. It is difficult to produce flat glass fiber of high quality, but in the present invention, it becomes possible to use cooling fins,
Flat glass fibers of more uniform quality can be stably manufactured.

A large number of the nozzle chips 13 having the above-described configuration are arranged on the lower surface of the nozzle plate 12. In this case, as shown in FIG. It is preferable to arrange the nozzle holes 24 in parallel with each other in such a manner that the major diameter directions thereof are parallel to each other. By adopting this arrangement, it is possible to arrange the cooling fins 15 between a plurality of nozzle tip rows formed by arranging the nozzle tips 13 in the major axis direction of the nozzle holes 24, and by adopting this configuration. The cooling fins 15 can uniformly cool the respective nozzle chips 13 and the molten glass discharged from the nozzle chips 13 and produce flat glass fibers of uniform quality.

Further, when the nozzle chips 13 are arranged with the major axis directions of the nozzle holes 24 parallel, as shown in FIG. 8, the longitudinal direction of the nozzle holes 24 is aligned with the short side 12a of the rectangular nozzle plate 12. It is preferable to arrange them so as to be parallel. With this configuration, the number of the nozzle tips 13 in the nozzle tip row parallel to the short side 12a can be reduced, and therefore the length of the nozzle tip row is shortened. Therefore, the length of the cooling fins 15 arranged along the nozzle tip row is shortened. it can. If the cooling fins 15 must be lengthened to cool many nozzle chips 13, the cooling capacity of the cooling fins is insufficient, and the degree of cooling differs depending on the location. As a result, the glass fibers from the nozzle tip where cooling is properly performed have a large aspect ratio, and the glass fibers from the nozzle tip with insufficient cooling have a small aspect ratio, and the variation in the aspect ratio is large in the same glass fiber bundle. Resulting in. On the other hand, by adopting the arrangement shown in FIG. 8, the cooling fins 15 can be shortened, and the nozzle tips 13 in the rows can be appropriately cooled to suppress the variation in the aspect ratio.

In FIG. 1, the nozzle plate 12 is arranged such that its longitudinal direction is parallel to the rotation axis of the sizing agent coating device 17 and the rotation axis of the winder 19 arranged below. As described above, the nozzle holes 24 are arranged so that the major axis direction is parallel to the short side 12a (see FIG. 8) of the nozzle plate 12 (and therefore, at right angles to the longitudinal direction). The number of nozzle tips 13 arranged in the major diameter direction is small, and the nozzle tip row is short.
For this reason, the angle of the flat glass fiber 14 drawn from each nozzle tip 13 in this nozzle tip row and traveling toward the sizing agent coating device 17 with respect to the tip end face of the nozzle tip does not have a large difference (in the drawing, the nozzle tip). Since the distance between the tip 13 and the sizing agent applying device 17 is shown small, it seems that there is an angle difference. However, in an actual device, the angle is large, so that there is not much angle difference.) The unevenness of the aspect ratio based on the angle difference when the molten glass discharged from 13 is stretched hardly occurs. From this point, the unevenness of the flatness ratio of the flat glass fiber in the glass fiber bundle can be reduced.

Conventionally, when the major axis direction of the nozzle hole 24 of the nozzle tip 13 is arranged at right angles to the rotation axis of the sizing agent application device 17 or the rotation axis of the winder 19, the flat glass fibers 14 It is thought that it will be bundled after coming into contact with the surface at a right angle and falling down at random, and it will be a glass fiber bundle with many gaps, in order to obtain a glass fiber bundle with few gaps, The nozzle holes are arranged so that the major axis direction thereof is parallel to the sizing agent application device 17. However, the present inventors have confirmed that the rotation axis of the sizing agent application device 17 in the major axis direction of the nozzle holes 24 is determined. Even if it was arranged at right angles, no difference was seen from the case where it was arranged in parallel, and it was found that the bundled fiber bundle had flat glass fibers arranged in the same direction, with few gaps.

The composition of the glass used in the present invention includes E glass, ECR glass, S glass, C glass, and D glass.
What is necessary is just what can manufacture glass fiber, such as glass, and it does not specifically limit. As for the thickness of the glass fiber produced by the nozzle tip of the present invention, those having various fiber diameters can be produced by setting the production conditions. However, the minor axis in the cross section is 3-20 μm, preferably 4 μm.
１５15 μm, longest diameter of 6-100 μm, preferably 15
Those having a size in the range of -80 µm are preferable in terms of production. That is, when the short diameter is less than 3 μm, spinning of the glass fiber itself is difficult, and when the long diameter exceeds 100 μm, the flattening efficiency is poor, the rigidity is too high, and efficient production cannot be performed.

[0031]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples for better understanding of the present invention, but the present invention is not limited to these examples.

Example 1 A nozzle tip 13 having the shape shown in FIGS. 2 to 4 was used. The nozzle hole 24 provided in the nozzle tip 13 has an oval cross section, a 5.2 mm long diameter,
The short diameter is 1.0 mm, the aspect ratio is 5.2, and the nozzle hole 24
Has a total length C of 1.6 mm. A pair of nozzle holes 24, 2
The distance (center-to-center distance) between the nozzle holes 4 is 2.3 mm, the length between the nozzle holes 24, 3.1 is 3.1 mm (60% of the long diameter of the nozzle hole), and the depth is 0.6 mm (for the nozzle portion 23). The nozzle hole wall cutout 25 of 37.5% of the effective length) was formed.

As shown in FIG. 8, six nozzle chips 13 are arranged at a pitch of 6.7 mm with respect to the nozzle plate 12 in a row parallel to the short side 12a.
In a row parallel to 2b, 40 pieces were arranged at a pitch of 7.0 mm. The nozzle plate 12 was attached to the apparatus shown in FIG. 1, and the melt of the E glass composition was spun at a spinning temperature of 1200 °.
C, spinning was performed at a spinning speed of 2000 m / min. The cross section of the spun filament was a substantially oval cross section having a major axis of 24.6 μm, a minor axis of 5.9 μm, and a reduced fiber diameter of 13.2 μm, and flat glass fibers could be obtained stably. The flattening ratio was 4.2, and the flattening efficiency (% of the flat ratio of the glass fiber to the flat ratio of the cross section of the nozzle hole) was 8.
0.8%, and the variation in the aspect ratio within the fiber bundle was small.

[0034]

As described above, according to the nozzle tip of the present invention, by disposing two nozzle holes close to each other with the major axis direction parallel to each other, the arrangement density of the nozzle holes can be increased and the nozzle plate per nozzle plate having a certain area can be provided. Can be increased, and further, by providing the nozzle hole wall cutout portion between the pair of nozzle holes, the flat glass fiber having a high aspect ratio such as an aspect ratio of 2 or more can be stably produced. Spinning can be performed at a high speed, and at the start of spinning, the spun molten glass does not stain the lower surface of the nozzle plate, and spinning can be started quickly.

Here, by setting the cutout depth of the cutout portion of the nozzle hole wall to 10 to 100% of the length of the effective nozzle portion, the flattening effect of the glass fiber by the cutout portion is excellent. Is obtained.

By providing a molten glass reservoir communicating with the pair of nozzle holes above the nozzle portion, the flow of the molten glass to the nozzle holes is stabilized, and the flattening effect of the glass fibers is further stabilized. The effect is obtained.

According to the flat glass fiber manufacturing apparatus of the present invention, a large number of nozzle chips having the above-described structure are arranged in a nozzle plate with the longitudinal direction and the longitudinal direction of the nozzle holes arranged in parallel in the longitudinal direction and the horizontal direction. By disposing cooling fins between a plurality of nozzle tip rows formed side by side and in the major axis direction of the nozzle holes, each nozzle tip can be uniformly and stably cooled by the cooling fins, and the flatness ratio is small. This has the effect that glass fiber bundles can be stably produced at high speed.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a flat glass fiber manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view of a nozzle tip used in the apparatus of FIG.

FIG. 3 is a schematic sectional view taken along the line XX of FIG. 2;

FIG. 4 is a schematic bottom view of the nozzle tip shown in FIG. 2;

FIG. 5 is a schematic bottom view showing a modified example of the nozzle tip.

FIG. 6 is a schematic sectional view showing another modified example of the nozzle tip.

FIG. 7 is a schematic sectional view showing still another modified example of the nozzle tip.

8 is a schematic bottom view showing a nozzle plate and cooling fins of the apparatus shown in FIG.

9A is a schematic cross-sectional view showing an example of the behavior of the molten glass discharged from a nozzle chip having a cutout formed outside a pair of nozzle holes, and FIG. 9B is a schematic sectional view showing the behavior of the molten glass discharged from the nozzle chip. Schematic sectional view showing another example of the behavior

FIGS. 10A, 10B, and 10C are schematic cross-sectional views each showing an example of a cross section of a flat glass fiber.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 glass melting furnace 12 nozzle plate 13 nozzle tip 14 glass fiber 15 cooling fin 16 water cooling unit 17 sizing agent coating device 18 sizing roller 19 winder 22 molten glass pooling unit 23 nozzle unit 24 nozzle hole 25 nozzle hole cutout

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G021 MA02 4L037 CS16 FA04 FA12 PA31 PF12 PF14 PF15 PF19 4L045 AA05 BA03 BA12 BA60 CB09 CB10 CB13 CB17 CB19 DA20 DC02

Claims (4)

[Claims] 1. A flat glass fiber spinning nozzle tip comprising a nozzle portion and at least a pair of nozzle holes penetrating the nozzle portion, wherein the pair of nozzle holes has a flat cross section and a long diameter direction. It is arranged in parallel, further on the nozzle hole wall of the region sandwiched between the pair of nozzle holes,
A flat glass fiber spinning nozzle tip, characterized in that a concave nozzle hole wall cutout is provided. 2. The notch depth of the concave nozzle hole wall notch portion is 10 to 100 with respect to the length of the effective nozzle portion.
%. The flat glass fiber spinning nozzle tip according to claim 1, wherein 3. The nozzle tip for flat glass fiber spinning according to claim 1, wherein a molten glass reservoir portion communicating with the pair of nozzle holes is provided above the nozzle portion. 4. A nozzle plate in which a plurality of flat glass fiber spinning nozzle chips according to claim 1 are arranged in a longitudinal direction and a lateral direction, and the major axis direction of the nozzle holes is arranged in parallel. And cooling fins arranged below the nozzle plate, wherein the cooling fins are arranged between a plurality of nozzle tip rows formed by arranging the nozzle tips in the longitudinal direction of the nozzle holes. A flat glass fiber manufacturing apparatus.