JP2022033465A - Bushing and method for manufacturing irregular shaped cross section glass fiber - Google Patents

Abstract

To provide a bushing that can stably manufacture a desired irregular shaped cross section glass fiber, and to provide a manufacturing method for manufacturing an irregular shaped cross section glass fiber using the bushing.SOLUTION: A bushing 4 includes: a base plate 41 extending in a predetermined one direction and including multiple cooling areas S in which a cooling member configured to be capable of cooling molten glass can be arranged; and multiple nozzles 5 including a nozzle hole 53 provided in the base plate 41 and formed into a flat shape in a tip part from which molten glass flows out, a pair of first wall parts 51 facing each other in a minor diameter direction of the nozzle hole 53 and having a recessed notch 54, and a pair of second wall parts 52 facing each other in a major diameter direction of the nozzle hole 53, where the multiple nozzles 5 are arranged so as to orient the first wall parts 51 in a direction of the cooling areas S.SELECTED DRAWING: Figure 3

Description

The present invention relates to an improvement in a technique for manufacturing a glass fiber having a modified cross section.

Irregular cross-section glass fiber having a non-circular cross-section such as an oval or elliptical cross-section is used in various fields because it can realize a high reinforcing effect when mixed with a resin and composited. There is.

This type of irregular cross-section glass fiber is generally produced by cooling while drawing molten glass from a bushing nozzle. At this time, since the cross-sectional shape of the manufactured glass fiber depends on the shape of the nozzle hole at the tip of the nozzle, when manufacturing a glass fiber having a modified cross section, the nozzle hole is often flattened at the tip of the nozzle. ..

However, even if a nozzle having a flat nozzle hole is used, if the viscosity of the molten glass drawn out from the nozzle is too low, the cross section of the molten glass is likely to be rounded due to surface tension directly under the tip of the nozzle. , It becomes impossible to produce the desired modified cross-section glass fiber.

Therefore, for example, in the nozzle of Patent Document 1, in the nozzle tip portion where the molten glass flows out, a concave notch is provided in each of the pair of long wall portions facing each other in the minor axis direction of the flat nozzle hole, and the concave shape is formed. The viscosity of the molten glass is adjusted by cooling with the notch.

JP-A-2017-226579

In recent years, it has been studied to improve productivity and to produce a strand having a large count by increasing the number of irregular cross-section glass fibers drawn from one bushing. As described in Patent Document 1, by arranging the cooling member near both notches, the number of nozzles provided in the bushing may be reduced, and the productivity of the irregular cross-section glass fiber may not be sufficiently increased.

Further, when the molten glass is cooled by arranging a cooling member near both notches, the molten glass may be cooled too much. Therefore, it may not be possible to stably form the irregular cross-section glass fiber.

In view of the above circumstances, it is an object of the present invention to stably produce a desired modified cross-section glass fiber.

The bushing according to the present invention comprises a base plate extending in a predetermined direction and having a plurality of cooling regions in which a cooling member configured to cool the molten glass can be arranged, and the molten glass provided on the base plate. At the tip of the nozzle hole, the flat nozzle hole faces the nozzle hole in the minor axis direction, and the pair of first wall portions having a concave notch face each other in the major axis direction of the nozzle hole. A glass fiber manufacturing apparatus comprising a pair of second wall portions and a plurality of nozzles comprising, wherein the plurality of nozzles are arranged so that the first wall portion faces toward the cooling region. Therefore, between the adjacent cooling regions, a first nozzle row in which a plurality of the nozzles are arranged at predetermined intervals along the extending direction of the cooling region, and the first nozzle row. A pair of the nozzles in the first nozzle row is arranged with a second nozzle row in which a plurality of the nozzles are arranged with a predetermined spacing along the extending direction of the cooling region. The nozzles of the first nozzle row are arranged so that each of the notches provided in the first wall portion of the above can face the cooling region.

According to such a configuration, since the first nozzle row and the second nozzle row are arranged between the cooling members, more nozzles can be arranged as compared with the conventional case. Therefore, the productivity of the irregularly shaped cross-section glass fiber can be improved, and a large number of glass fibers can be obtained at one time, so that a strand having a large count can be manufactured.
Further, for the nozzles included in the first nozzle row, one notch directly faces the cooling member, and the other notch faces the cooling member through the region of the gap between the nozzles of the second nozzle row. It is possible to prevent the molten glass from being overcooled. Therefore, the viscosity of the molten glass at the time of molding can be appropriately adjusted, and the irregular cross-section glass fiber can be stably molded.
If the other notch faces only the nozzles in the second nozzle row, the molten glass is not cooled.

In the present invention, the nozzles of the second nozzle row are provided so that each of the notches provided in the pair of first wall portions of the nozzles in the second nozzle row can face the cooling region. Is preferably arranged.

According to such a configuration, even in the molten glass drawn from the nozzles included in the second nozzle row, the viscosity of the molten glass at the time of molding can be appropriately adjusted, and the deformed cross-section glass fiber can be stably molded. can.

In the present invention, the distance between the plurality of nozzles in the first nozzle row and between the plurality of nozzles in the second nozzle row is preferably narrower than the width of the tip of the notch of the nozzle in the nozzle. ..

With such a configuration, it is possible to reliably prevent the molten glass from being overcooled.

The method for producing a modified cross-section glass fiber according to the present invention is characterized in that the modified cross-section glass fiber is produced by using the bushing described above. According to such a configuration, the same effect as the configuration already described can be obtained.

In the present invention, it is preferable that the molten glass is E glass. Since the E glass is a glass that does not easily devitrify, the productivity of the irregular cross-section glass fiber is improved.

In the present invention, the molten glass preferably has a viscosity of 10 ^2.0 to 10 ^3.5 dPa · s at the molding temperature. That is, when it is 103.5 dPa ^· s or less, the viscosity of the molten glass does not become too high, so that the moldability of the glass fiber can be well maintained. Further, when it is 10 ^2.0 dPa · s or more, the viscosity of the molten glass does not become too low, so that the force of the molten glass to return to the circular cross section is weakened by the surface surface force, and the flatness ratio (major axis) of the glass fiber is weakened. Dimension / minor axis dimension) can be increased.

According to the present invention, a desired modified cross-section glass fiber can be stably produced.

FIG. 1 is a cross-sectional view showing a modified cross-sectional glass fiber manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing the periphery of the bushing nozzle of FIG. FIG. 3 is an enlarged bottom view showing the periphery of the bushing nozzle of FIG. 1. 4A and 4B are views showing a bushing nozzle according to an embodiment of the present invention, in which FIG. 4A is a side view thereof, FIG. 4B is a sectional view taken along the line A1-A1 of FIG. It is a cross-sectional view of B1-B1 of. FIG. 5 is an enlarged bottom view showing the periphery of the bushing nozzle of FIG. FIG. 6 is an enlarged bottom view showing the periphery of the bushing nozzle according to the comparative example.

Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Further, in each drawing, members having substantially the same function may be referred to by the same reference numeral.

(One Embodiment of the manufacturing apparatus and manufacturing method of the irregular cross-section glass fiber)
As shown in FIG. 1, the modified cross-section glass fiber manufacturing apparatus 10 according to the present embodiment includes a glass melting furnace 1, a fore hearth 2 connected to the glass melting furnace 1, and a feeder 3 connected to the fore hearth 2. ing. Here, in the Cartesian coordinate system consisting of XYZ shown in FIG. 1, the X direction and the Y direction are the horizontal direction, and the Z direction is the vertical direction (hereinafter, the same applies).

The molten glass G is supplied from the glass melting furnace 1 to the feeder 3 through the fore hearth 2 and is stored in the feeder 3. Although one feeder 3 is shown in FIG. 1, a plurality of feeders 3 may be connected to the glass melting furnace 1. Further, a clarification furnace may be provided between the glass melting furnace 1 and the fore hearth 2.

In this embodiment, the molten glass G is made of E glass, but may be another glass material such as D glass, S glass, AR glass, and C glass.

A bushing 4 is arranged at the bottom of the feeder 3. The bushing 4 is attached to the feeder 3 via a bushing block or the like. The bottom of the bushing 4 is composed of a base plate 41 as shown in FIG. 2, and the base plate 41 is provided with a plurality of nozzles 5. Further, the base plate 41 is provided with a plurality of cooling regions S extending in the Y direction, which is a predetermined direction, in which the cooling pipe 6 can be arranged (see FIG. 3). A cooling pipe 6 as a cooling member is provided in the cooling region S.

The molten glass G stored in the feeder 3 is pulled out downward from a plurality of nozzles 5 provided on the base plate 41 of the bushing 4, and glass fiber (monofilament) Gm is manufactured. At this time, the viscosity of the molten glass G at the molding temperature is set in the range of 10 ^2.0 to 10 ^3.5 dPa ^· s (preferably 10 ^2.5 to 10 3.3 dPa · s). The viscosity of the molten glass G at the molding temperature is the viscosity of the molten glass G at the position where it flows into the nozzle 5. A sizing agent is applied to the surface of the glass fiber Gm by an applicator (not shown), and 100 to 10,000 fibers are spun into one strand Gs. The count of the strand Gs depends on the glass fiber Gm to be spun, and the larger the number of glass fibers Gm, the larger the count of the strand Gs. The spun strands Gs are wound around the collet 7 of the winding device as a fiber bundle Gr. The strands Gs are cut into a predetermined length of, for example, about 1 to 20 mm and used as chopped strands.

The glass melting furnace 1, the fore hearth 2, the feeder 3, the bushing 4, the nozzle 5, and the cooling pipe 6 are at least partially formed of platinum or a platinum alloy (for example, a platinum rhodium alloy).

In order to adjust the viscosity of the molten glass G, one or more elements selected from the fore hearth 2, the feeder 3 and the bushing 4 may be heated by energization heating or the like.

As shown in FIGS. 2 and 3, the nozzle 5 has a pair of long wall portions (first wall portions) 51 facing each other in the X direction and a pair of short walls facing each other in the Y direction at the tip portion (lower portion). It includes a wall portion (second wall portion) 52, and a flat (oval in this embodiment) nozzle hole 53 partitioned by a long wall portion 51 and a short wall portion 52. A notch 54 is provided in each long wall portion 51, and a part of the nozzle hole 53 communicates with the external space of the nozzle 5 through the notch 54. In this embodiment, the major axis direction of the nozzle hole 53 coincides with the Y direction, and the minor axis direction of the nozzle hole 53 coincides with the X direction. Further, in this embodiment, the X-direction dimension of the short wall portion 52 is shorter than the Y-direction dimension of the long wall portion 51. Of course, these dimensional relationships of the wall portions 51 and 52 are not particularly limited. Further, the cross-sectional shape of the nozzle hole 53 may be an elliptical shape or the like as well as an oval shape.

As shown in FIGS. 4A to 4C, the notch 54 provided in each long wall portion 51 of the nozzle 5 has a trapezoidal shape having the same dimensions. Specifically, in this embodiment, the notch 54 has an isosceles trapezoidal shape (upper base) that has a center point T1 of the upper base on the center line M1 of the long wall portion 51 and is symmetrical with respect to the center line M1. Is shorter than the bottom). The internal angle θ1 (internal angles on both sides of the upper base) is, for example, more than 90 ° to 160 ° (preferably 110 ° to 150 °). In this embodiment, the nozzle hole 53 has a flat oval shape and a constant shape in the Z direction. As shown in FIG. 4 (c), at the tip of the nozzle 5, the nozzle hole 53 has a ratio (a / b) of the X-direction dimension (minor-diameter dimension) b to the Y-direction dimension (major-diameter dimension) a. It is in the range of 5 to 20 (preferably 3 to 10).

According to such a configuration, it is possible to sufficiently secure the opening area of the notch 54 while suppressing the shape deformation caused by the notch 54 of the nozzle 5. Therefore, the glass fiber Gm having a deformed cross section having a non-circular cross section such as a flat shape can be stably molded. In other words, the variation in the cross-sectional shape of the manufactured glass fiber Gm is reduced.

If the nozzle 5 has a flat nozzle hole 53 partitioned by a long wall portion 51 and a short wall portion 52 at the tip portion, the shape of the base end portion (upper portion) is the shape of the tip portion of the nozzle 5. It may be the same as or different from.

It is preferable that 200 to 10,000 nozzles 5 are arranged on the base plate 41. By arranging the above number of nozzles 5, strands Gs having a large count can be obtained. It is preferable that 1500 or more nozzles 5 are arranged on the base plate 41.

The cooling pipe 6 circulates cooling water F as a fluid inside the cooling pipe 6 to exert a cooling action. The cooling pipe 6 is a plate-shaped body, and a plurality of cooling pipes 6 are arranged so that the plate surface thereof follows a certain direction (vertical direction). In this embodiment, the cooling pipe 6 is integrally provided in the cooling region S of the base plate 41, but may be provided separately from the bottom of the bushing 4. Further, the cooling pipe 6 may be a circular tubular body. The height position of the cooling pipe 6 can be appropriately adjusted according to the cooling conditions of the molten glass G. For example, the cooling pipe 6 may be arranged above the tip of the nozzle 5 so as not to directly face the molten glass G drawn out from the nozzle 5, or the molten glass G drawn out from the nozzle 5 and the nozzle 5. It may be arranged so as to straddle both of them. The cooling member is not limited to the cooling pipe 6, and may be a cooling fin or the like that induces an air flow to exert a cooling action.

As shown in FIGS. 3 and 5, in the base plate 41 of the bushing 4, a plurality of nozzle rows L1 and L2 are arranged in parallel at intervals in the X direction between adjacent cooling regions S. Each of the nozzle rows L1 and L2 is configured by arranging a plurality of nozzles 5 having the major axis direction of the nozzle holes 53 oriented in the Y direction on the same straight line extending in the Y direction. The cooling pipe 6 is arranged between the nozzle rows L1 and L2 adjacent to each other in the X direction in parallel with the nozzle rows L1 and L2. In the present embodiment, the nozzle row L1 and the nozzle row L2 are the same except for the arrangement position of the nozzle 5 in the Y direction. As a result, as shown in FIG. 5, the cooling pipe 6 faces the notch 54a of the nozzle 5 adjacent to the cooling pipe 6, and the molten glass G flowing in the nozzle 5 is cooled through the notch 54a. ing. Specifically, at the tip of the nozzle 5, the molten glass G is rapidly cooled from a temperature of 1000 ° C. or higher by the cooling tube 6. The cooling pipe 6 also has a function of cooling the bushing 4 and the nozzle 5 to suppress thermal deterioration thereof and improve durability.

Further, the notch 54b of the nozzle 5 not adjacent to the cooling pipe 6 is also included in the adjacent nozzle row (the nozzle row adjacent to the nozzle row L1 is L2, and the nozzle row adjacent to the nozzle row L2 is L1). Since it faces the cooling member 6 through the region of the gap between the nozzles 5, it is possible to prevent the molten glass G from being overcooled. Therefore, the viscosity of the molten glass G at the time of molding can be appropriately adjusted, and the irregular cross-section glass fiber can be stably molded. That is, the molten glass G on the notch 54a side of the nozzle 5 is rapidly cooled because it directly faces the cooling tube 6, and the molten glass G on the notch 54b side of the nozzle 5 is separated from the cooling tube 6 by a predetermined distance. It is cooled more slowly than the molten glass G on the side of the notch 54a in order to face the surface. Therefore, the molten glass G on the notch 54a side is immediately solidified and hardly deformed, while the molten glass G on the notch 54b side is deformable to some extent until it is solidified. In order to stably form a deformed cross-section glass fiber with a high flatness, it is necessary to rapidly harden only a part of the molten glass G to prevent the cross section of the fiber from becoming round, while gradually hardening the other parts. There is. For example, if the molten glass G on both major axis sides is rapidly solidified, the flatness becomes high, but the glass fiber is likely to be cut.

As shown in FIG. 6, the molten glass G is not sufficiently cooled unless the notch 54b of the nozzle 5 which is composed of only the nozzle row L1 and is not adjacent to the cooling pipe 6 faces the cooling member 6.

In this embodiment, the intervals D1 and D2 are narrower than the width W at the tips of the notches 54a and 54b. Therefore, it is possible to prevent the molten glass G from being overcooled.

The distances D1 and D2 between the nozzles 5 are preferably 1 to 10 mm, more preferably 1 to 5 mm. As a result, more nozzles 5 can be arranged on the base plate 41. Further, the width W at the tip of the notch 54 is preferably 2 to 20 mm. The ratio of the width W (W / D (D1, D2)) between the intervals D1 and D2 and the tip of the notch 54 can be, for example, 0.5 to 5, but 1.1 to 2. It is preferably 5.

The number of nozzles 5 included in one nozzle row L1 and L2 is preferably 10 to 500 or less.

According to the present embodiment for producing the irregular cross-section glass fiber as described above, the following action and effect can be obtained.

In the present embodiment, since the first nozzle row L1 and the second nozzle row L2 are arranged between the cooling regions S (cooling pipe 6), more nozzles 5 can be arranged as compared with the conventional case. .. Therefore, the productivity of the irregular cross-section glass fiber can be improved. Further, since many nozzles 5 are arranged, the number of glass fibers Gm obtained at one time is increased, and as a result, strands Gs having a large count can be manufactured. Further, for the nozzle 5 included in the first nozzle row L, one notch 54a directly faces the cooling pipe 6, and the other notch 54b passes through the region of the gap between the nozzles 5 of the second nozzle row L2. Since it faces the cooling pipe 6, it is possible to prevent the molten glass G from being overcooled. Therefore, the viscosity of the molten glass G at the time of molding can be appropriately adjusted, and the irregular cross-section glass fiber can be stably molded.

Further, regarding the nozzle 5 included in the second nozzle row L, one notch 54a directly faces the cooling pipe 6, and the other notch 54b passes through the region of the gap between the nozzles 5 of the first nozzle row L1. Since it faces the cooling pipe 6, it is possible to prevent the molten glass G from being overcooled.

Although the method for producing a modified cross-section glass fiber according to an embodiment of the present invention has been described above, the present invention is not limited to this, and various variations are possible without departing from the gist thereof.

In the above embodiment, the intervals D1 and D2 between the nozzles 5 are equal, but they may be different. In that case, the ratio D1 / D2 of D1 and D2 is preferably in the range of 0.5 to 2.0.

1: Glass melting furnace, 4: Bushing, 41: Base plate, 5: Nozzle, 51: Long wall part (first wall part), 52: Short wall part (second wall part), 53: Nozzle hole, 54: Notch, 6: Cooling tube, 10: Deformed cross-section glass fiber manufacturing equipment, G: Fused glass, Gm: Glass fiber (monofilament), Gs: Strand, S: Cooling region, L1: 1st nozzle row, L2: 2nd Nozzle row, W: Notch opening width

Claims (6)

A base plate extending in a predetermined direction and having a plurality of cooling regions in which a cooling member configured to cool the molten glass can be arranged.
A pair of first wall portions provided on the base plate and having a concave notch facing the nozzle hole having a flat shape in the minor axis direction at the tip portion where the molten glass flows out. And a plurality of nozzles comprising a pair of second wall portions facing each other in the major axis direction of the nozzle holes.
The first wall portion is a bushing in which a plurality of the nozzles are arranged so as to face the direction of the cooling region.
Between the adjacent cooling regions, a first nozzle row in which a plurality of the nozzles are arranged at predetermined intervals along the extending direction of the cooling region,
A second nozzle row in which a plurality of the nozzles are arranged with a predetermined spacing is arranged along the extending direction of the cooling region while having an interval from the first nozzle row.
The nozzles of the first nozzle row are arranged so that each of the notches provided in the pair of first wall portions of the nozzles in the first nozzle row can face the cooling region. , Bushing. The nozzles of the second nozzle row are arranged so that each of the notches provided in the pair of first wall portions of the nozzles in the second nozzle row can face the cooling region. The bushing according to claim 1. The first or second claim, wherein the distance between the plurality of nozzles in the first nozzle row and between the plurality of nozzles in the second nozzle row is narrower than the width of the tip of the notch of the nozzle in the nozzle. Bushing. A method for producing a modified cross-section glass fiber using the bushing according to any one of claims 1 to 3. The method for producing a modified cross-section glass fiber according to claim 4, wherein the molten glass is E glass. The method for producing a modified cross-section glass fiber according to claim 4 or 5, wherein the molten glass has a viscosity of 10 ^2.0 to 10 ^3.5 dPa · s at a molding temperature.

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