TWI865804B - Liner and special-section glass fiber manufacturing method - Google Patents

Abstract

[Topic] Stable production of desired irregular cross-section glass fibers. [Solution] A sleeve (4) comprises: a plurality of nozzles (5) having nozzle holes (53) with flat cross-sections at the front end; and a base plate (41) having a plurality of cooling areas (S) extending in a predetermined single direction and capable of being equipped with cooling components, the cooling components being used to cool the molten glass (G) flowing out from the front end of the plurality of nozzles (5); in the front end, the nozzle holes (53) comprise: a pair of first wall portions (51) having concave notches (54) facing each other in the short diameter direction of the flat cross-section, and a pair of second wall portions (52) facing each other in the long diameter direction of the flat cross-section; the flat The major diameter direction of the cross section is the extension direction of the cooling zone (S); in the base plate, between adjacent cooling zones (S), there are arranged at intervals: a first nozzle row (L1), which is a plurality of nozzles (5) arranged at predetermined intervals along the extension direction of the cooling zone (S); and a second nozzle row (L2), which is a plurality of nozzles (5) arranged at predetermined intervals along the extension direction of the cooling zone (S); the plurality of nozzles (5) of the first nozzle row (L1) are arranged in such a way that each of the notches (54) provided in a pair of first wall portions in the first nozzle row (L1) faces the cooling zone (S).

Description

Liner and special-section glass fiber manufacturing method

The present invention is an improvement on the manufacturing technology of glass fiber with special cross-section.

When glass fibers with irregular cross-sections such as oblong or elliptical flat cross-sections have a high reinforcement effect when mixed with resins, they are used in various fields.

Such irregular cross-section glass fibers are generally manufactured by drawing molten glass from a sleeved nozzle while cooling it. At this time, the cross-sectional shape of the manufactured glass fiber depends on the shape of the nozzle hole at the front end of the nozzle, so in the case of manufacturing irregular cross-section glass fibers, the nozzle hole at the front end of the nozzle is often made flat.

However, even if a nozzle having a flat nozzle hole is used, if the viscosity of the molten glass drawn from the nozzle is too low, the cross section of the molten glass will easily be rounded due to surface tension just below the nozzle tip, and the desired irregular cross-section glass fiber cannot be produced.

Here, for example, in the nozzle of Patent Document 1, a concave notch is provided on each of a pair of long wall portions facing each other in the short diameter direction of a flat nozzle hole at the front end of the nozzle from which molten glass flows out, and the viscosity of the molten glass is adjusted by cooling through the concave notch. [Prior Technical Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2017-226579

In recent years, there has been a review of increasing the number of irregular cross-section glass fibers pulled out from a liner to improve productivity or produce thicker ropes. As described in Patent Document 1, by arranging cooling members near the notches on both sides, the number of nozzles provided in the liner is reduced, but there is a situation where the productivity of irregular cross-section glass fibers cannot be sufficiently improved.

Furthermore, when cooling members are placed near the notches on both sides to cool the molten glass, the molten glass may be overcooled, and thus, it may not be possible to stably form a glass fiber with an irregular cross section.

In view of the above practical situation, the subject of the present invention is to stably manufacture the desired special-shaped cross-section glass fiber.

The bushing of the present invention comprises: a plurality of nozzles, each of which has a nozzle hole with a flat cross section at the front end, and a base plate, which has a plurality of cooling areas extending in a predetermined single direction and capable of being provided with a cooling member, the cooling member being used to cool the molten glass flowing out from the front end of the plurality of nozzles; in the front end, the nozzle hole comprises: a pair of first wall portions, each of which has a concave notch facing each other in the short diameter direction of the flat cross section, and a pair of second wall portions facing each other in the long diameter direction of the flat cross section; the long diameter direction of the flat cross section is the extension direction of the aforementioned cooling area; in the aforementioned base plate, between the adjacent aforementioned cooling areas, there are arranged at intervals: a first nozzle row, which is formed by arranging the aforementioned plurality of nozzles at a predetermined interval along the extension direction of the aforementioned cooling area, and a second nozzle row, which is formed by arranging the aforementioned plurality of nozzles at a predetermined interval along the extension direction of the aforementioned cooling area; the aforementioned plurality of nozzles of the aforementioned first nozzle row are arranged in a manner that each of the aforementioned notches provided in the aforementioned pair of first wall portions in the aforementioned first nozzle row faces the aforementioned cooling area.

According to this structure, since the first nozzle row and the second nozzle row are arranged between the cooling members, more nozzles can be arranged than before. Therefore, the productivity of irregular cross-section glass fibers can be improved, and a large number of glass fibers can be obtained at one time, so thicker ropes can be manufactured.

In addition, the nozzles included in the first nozzle row have one notch facing the cooling member directly, and the other notch faces the cooling member through the gap area between the nozzles of the second nozzle row, so that the molten glass can be prevented from being overcooled. Therefore, the viscosity of the molten glass during forming is appropriately adjusted, and the glass fiber with a special cross section can be formed stably.

Furthermore, if the other notch is only facing the nozzle of the second nozzle row, the molten glass will not be cooled.

In the liner of the present invention, the plurality of nozzles of the second nozzle row are preferably arranged in such a manner that each of the notches provided in the pair of first wall portions in the second nozzle row faces the cooling area.

According to this structure, even if it is molten glass drawn from the nozzles included in the second nozzle row, the viscosity of the molten glass during forming can be appropriately adjusted, and glass fibers with irregular cross-sections can be formed stably.

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

This structure can reliably prevent the molten glass from being overcooled.

The method for manufacturing a glass fiber with a special cross section of the present invention is characterized in that the glass fiber with a special cross section is manufactured using the above-mentioned liner. According to this structure, the same effect as the above-mentioned structure can be obtained.

In the method for manufacturing irregular cross-section glass fibers of the present invention, the aforementioned molten glass is preferably E glass. E glass is a glass that is difficult to devitrify, thus improving the productivity of irregular cross-section glass fibers.

In the method for manufacturing a glass fiber with a special cross section of the present invention, it is preferred that the molten glass has a viscosity of 10 ^2.0 to 10 ^3.5 dPa. s at the forming temperature. That is, if the viscosity is below 10 ^3.5 dPa. s, the viscosity of the molten glass will not become too high, so the formability of the glass fiber can be well maintained. Moreover, if the viscosity is above 10 ^2.0 dPa. s, the viscosity of the molten glass will not become too low, so the force that causes the molten glass to return to a circular cross section by the surface force will be weakened, and the flatness ratio (long diameter dimension/short diameter dimension) of the glass fiber can be improved.

According to the present invention, desired irregular cross-section glass fibers can be stably manufactured.

The following is a description of a preferred embodiment. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. In addition, in each figure, components having substantially the same function are referenced by the same symbols. The numerical range represented by "~" in this specification represents a range that includes the numerical values recorded before and after "~" as the minimum and maximum values.

(One embodiment of a manufacturing device and a manufacturing method for irregular cross-section glass fiber) As shown in FIG1, the manufacturing device 10 for irregular cross-section glass fiber of this embodiment comprises: a glass melting furnace 1, a forehearth 2 connected to the glass melting furnace 1, and a feeding section 3 connected to the forehearth 2. Here, in the rectangular coordinate system formed by XYZ shown in FIG1, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction (the same applies hereinafter).

Molten glass G is supplied from the glass melting furnace 1 to the feeder 3 through the forehearth 2 and stored in the feeder 3. Although FIG. 1 shows one feeder 3, a plurality of feeders 3 may be connected to the glass melting furnace 1. Furthermore, a fining furnace may be provided between the glass melting furnace 1 and the forehearth 2.

In this embodiment, the molten glass G is made of E glass (alkali-free glass), but it may be other glass materials such as D glass (low dielectric glass), S glass (high-strength glass), AR glass (alkali-resistant glass), C glass (acid-resistant glass), etc.

A bushing 4 is arranged at the bottom of the feed part 3. The bushing 4 is mounted on the feed part 3 through a bushing block or the like. The bottom of the bushing 4 is formed by a base plate 41 as shown in FIG. 2 , and a plurality of nozzles 5 are arranged on the base plate 41. In addition, a plurality of cooling areas S are arranged on the base plate 41, which extend in a predetermined single direction, that is, in the Y direction, and can be arranged with cooling pipes 6 (see FIG. 3 ). In addition, the cooling area S is provided with cooling pipes 6 as cooling members.

The molten glass G stored in the feed section 3 is pulled downward from a plurality of nozzles 5 provided on a base plate 41 of a liner 4 to produce glass fibers (single fibers) Gm. At this time, the viscosity of the molten glass G at the forming temperature is preferably set within a range of 10 ^2.0 to 10 ^3.5 dPa･s (more preferably 10 ^2.5 to 10 ^3.3 dPa･s). The viscosity of the molten glass G at the forming temperature is the viscosity of the molten glass G at the position where the nozzles 5 flow. A sizing agent is applied to the surface of the glass fibers Gm by an applicator (not shown), and 100 to 10,000 glass fibers Gm are spun into a rope Gs. The thickness of the rope Gs depends on the number of the spun glass fibers Gm. The greater the number of the glass fibers Gm, the greater the thickness of the rope Gs. The spun rope Gs is wound up as a fiber bundle Gr by a reel 7 of a winding device. The rope Gs is cut into predetermined lengths of about 1 to 20 mm, for example, and used as a rope segment.

The glass melting furnace 1, the forehearth 2, the feed section 3, the liner 4, the nozzle 5 and the cooling tube 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 forehearth 2, the feeder 3, and the liner 4 may be heated by electric heating or the like.

As shown in FIG. 2 and FIG. 3 , the nozzle 5 has, at the front end portion (lower side portion), a pair of long wall portions (first wall portion) 51 facing each other in the X direction, a pair of short wall portions (second wall portion) 52 facing each other in the Y direction, and a nozzle hole 53 having a flat (oblong in this embodiment) cross section defined by the long wall portion 51 and the short wall portion 52. A notch 54 is provided in each long wall portion 51 so that a portion of the nozzle hole 53 is connected to the external space of the nozzle 5 through the notch 54. In this embodiment, the long diameter direction of the cross section of the nozzle hole 53 is consistent with the Y direction, and the short diameter direction of the cross section of the nozzle hole 53 is consistent with the X direction. In addition, 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, there is no particular limitation on the dimensional relationship between the long wall portion 51 and the short wall portion 52. Furthermore, the cross-sectional shape of the nozzle hole 53 may be an elliptical shape or the like in addition to an oblong shape.

As shown in Fig. 4 (a) to (c), the notch 54 provided in each long wall portion 51 of the nozzle 5 is a trapezoidal shape of the same size. Here, the molten glass flows out from the front end of the nozzle 5 in the direction below the Z direction shown in Fig. 4 (a). In detail, in this embodiment, the notch 54 has an upper center point T1 on the center line M1 of the long wall portion 51, and is an equilateral trapezoidal shape symmetrical to the center line M1 (the upper side is shorter than the lower side). The internal angle θ1 (the internal angle on both sides of the upper side) is, for example, 90° to 160° (preferably 110° to 150°). In addition, in this embodiment, the cross-section of the nozzle hole 53 is a flat oblong, which is a fixed shape in the Z direction. As shown in FIG. 4( c ), at the front end of the nozzle 5 , the ratio (a/b) of the X-direction dimension (minor diameter dimension) b to the Y-direction dimension (major diameter dimension) a of the cross section of the nozzle hole 53 is preferably in the range of 1.5 to 20 (more preferably 3 to 10).

According to this structure, the shape deformation of the notch 54 caused by the nozzle 5 can be suppressed, and the opening area of the notch 54 can be sufficiently ensured. Therefore, the glass fiber Gm having an irregular cross section having a non-circular cross section such as a flat shape can be stably formed. In other words, the cross-sectional shape error of the manufactured glass fiber Gm is reduced.

The nozzle 5 has a nozzle hole 53 at the front end, and if it has a flat cross-section formed by the long wall portion 51 and the short wall portion 52, the shape of the base end portion (upper side portion) may be the same as or different from the shape of the front end portion of the nozzle 5.

It is preferable that 200 to 10,000 nozzles 5 are arranged on the base plate 41. By arranging the nozzles 5 to the above number, a rope Gs with a larger thickness can be obtained. In addition, it is preferable that 1,500 or more nozzles 5 are arranged on the base plate 41.

The cooling tube 6 circulates cooling water F as a fluid inside thereof to exert a cooling effect. The cooling tube 6 is a plate-shaped body, and a plurality of the cooling tubes 6 are arranged in a certain direction (vertical direction) along the plate surface. In the present embodiment, the cooling tube 6 is integrally provided in the cooling area S of the base plate 41, but it may also be separately provided from the bottom of the liner 4. Furthermore, the cooling tube 6 may be a circular tube-shaped body. The height position of the cooling tube 6 may be appropriately adjusted according to the cooling conditions of the molten glass G. For example, the cooling tube 6 may be arranged above the front end of the nozzle 5 in a manner not directly facing the molten glass G pulled out from the nozzle 5, or it may be arranged in a manner spanning both the nozzle 5 and the molten glass G pulled out from the nozzle 5. The cooling member is not limited to the cooling tube 6, and may be a cooling fin or the like that guides air flow to exert a cooling effect.

As shown in Fig. 3 and Fig. 5, a plurality of nozzle rows L1 and L2 are arranged in parallel with each other at intervals in the X direction between adjacent cooling areas S in the base plate 41 of the bushing 4. Each nozzle row L1 and L2 is configured by arranging a plurality of nozzles 5 on the same straight line extending in the Y direction, and the nozzle 5 is configured such that the major diameter direction of the cross section of the nozzle hole 53 faces the Y direction. The cooling pipe 6 is arranged between the nozzle rows L1 and L2 adjacent in the X direction and in parallel with the nozzle rows L1 and L2. In the present embodiment, the nozzle rows L1 and L2 are the same except for the different arrangement positions of the nozzles 5 in the Y direction. As shown in FIG5 , the cooling tube 6 faces the notch 54a of the nozzle 5 adjacent to the cooling tube 6, and the molten glass G flowing in the nozzle 5 is cooled through the notch 54a. Specifically, at the front end of the nozzle 5, the molten glass G is rapidly cooled from a temperature of more than 1000°C by the cooling tube 6. In addition, the cooling tube 6 also has the function of cooling the liner 4 or the nozzle 5 to suppress the thermal deterioration of the same and improve the durability.

Furthermore, regarding the notch 54b of the nozzle 5 not adjacent to the cooling tube 6, the cooling member 6 is opposed to each other through the area of the gap between the nozzles 5 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), so that the molten glass G can be suppressed from being overcooled. Therefore, the viscosity of the molten glass G during forming can be appropriately adjusted, and the glass fiber with a special cross section can be formed stably. That is, the molten glass G on the notch 54a side of the nozzle 5 is directly opposite to the cooling tube 6 and is rapidly cooled, while the molten glass G on the notch 54b side of the nozzle 5 is spaced a predetermined distance away from the cooling tube 6 and is therefore cooled more slowly than the molten glass G on the notch 54a side. Therefore, the molten glass G on the notch 54a side solidifies quickly and becomes difficult to deform, while the molten glass G on the notch 54b side may still be deformed to a certain extent before solidification. In order to stably form a glass fiber with a high flatness and an irregular cross section, it is necessary to rapidly solidify only a portion of the molten glass G to suppress the rounding of the fiber cross section, and to slowly solidify the other portion. For example, if the molten glass G on both long diameter sides is rapidly solidified, the flatness is high, but the glass fiber is easily cut.

Furthermore, the notches 54a and 54b of at least the nozzle 5 of the nozzle row L1 may be of the above-mentioned structure, and the notches 54a and 54b of the nozzle 5 of both the nozzle rows L1 and L2 may be of the above-mentioned structure. Furthermore, as shown in FIG6 , if the notches 54b of the nozzle 5 not adjacent to the cooling tube 6 formed by only the nozzle row L1 are not opposite to the cooling member 6, the molten glass G cannot be sufficiently cooled. That is, if the notches 54b of the nozzle 5 not adjacent to the cooling tube 6 are opposite to other nozzles 5, the molten glass G cannot be sufficiently cooled.

In the present embodiment, the intervals D1 and D2 are narrower than the opening width W of the notches 54a and 54b. Therefore, it is possible to suppress the molten glass G from being excessively cooled.

The intervals D1 and D2 between the nozzles 5 are preferably 1 to 10 mm, more preferably 1 to 5 mm. In this way, more nozzles 5 can be arranged on the base plate 41. In addition, the opening width W of the notch 54 is preferably 2 to 20 mm. In addition, the ratio (W/D1) of the interval D1 to the opening width W of the notch 54, and the ratio (W/D2) of the interval D2 to the opening width W of the notch 54 can be, for example, 0.5 to 5, but preferably 1.1 to 2.5.

Furthermore, the number of nozzles 5 included in one nozzle row L1 or L2 is preferably 10 to 500 or less.

As described above, according to this embodiment of manufacturing a glass fiber with a special cross section, the following effects can be obtained.

In this embodiment, since the first nozzle row L1 and the second nozzle row L2 are arranged between the cooling area S (cooling tube 6), more nozzles 5 can be arranged compared with the conventional method. Therefore, the productivity of the glass fiber with a special cross section can be improved. Moreover, since more nozzles 5 are arranged, the number of glass fibers Gm that can be obtained at one time increases, and as a result, a thicker rope Gs can be manufactured. In addition, the nozzles 5 included in the first nozzle row L have one notch 54a directly facing the cooling tube 6, and the other notch 54b faces the cooling tube 6 via the gap area between the nozzles 5 of the second nozzle row L2, so that the molten glass G can be prevented from being overcooled. Therefore, the viscosity of the molten glass G during forming can be appropriately adjusted, and the glass fiber with a special cross section can be formed stably.

In addition, for the nozzles 5 included in the second nozzle row L, the notch 54a on one side is directly opposite to the cooling tube 6, and the notch 54b on the other side is opposite to the cooling tube 6 through the gap area between the nozzles 5 of the first nozzle row L1, so that the molten glass G can be suppressed from being overcooled.

Although the method for producing a glass fiber with a special cross section according to the embodiment of the present invention has been described above, the present invention is not limited thereto and various modifications can be made without departing from the scope of the present invention.

In the above embodiment, although the intervals D1 and D2 between the nozzles 5 are equal, they may be different. In this case, the ratio D1/D2 of D1 to 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 (first wall) 52: Short wall (second wall) 53: Nozzle hole 54: Notch 6: Cooling tube 10: Irregular cross-section glass fiber manufacturing device G: Molten glass Gm: Glass fiber (single fiber) Gs: Strand S: Cooling area L1: First nozzle row L2: Second nozzle row W: Opening width of notch

[Figure 1] Figure 1 is a cross-sectional view of a glass fiber manufacturing apparatus with a special cross-section showing an embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view showing the nozzle periphery of the sleeve of Figure 1 in an enlarged manner. [Figure 3] Figure 3 is a bottom view showing the nozzle periphery of the sleeve of Figure 1 in an enlarged manner. [Figure 4] Figure 4 is a view showing the nozzle of the sleeve of one embodiment of the present invention, (a) is a side view thereof, (b) is an A1-A1 cross-sectional view of (a), and (c) is a B1-B1 cross-sectional view of (a). [Figure 5] Figure 5 is a bottom view showing the nozzle periphery of the sleeve of Figure 3 in an enlarged manner. [Fig. 6] Fig. 6 is an enlarged bottom view showing the nozzle periphery of the liner of the comparative example.

4: Lining

41: Base plate

5: Nozzle

51: Long wall section (first wall section)

52: Short wall part (second wall part)

53: Nozzle hole

54: Gap

6: Cooling tube

S: Cooling area

L1: Nozzle row 1

L2: Nozzle row 2

Claims (10)

A bushing comprises: a plurality of nozzles, each of which has a nozzle hole with a flat cross section at the front end, and a base plate, which has a plurality of cooling areas extending in a predetermined single direction and capable of being provided with a cooling member, the cooling member being used to cool molten glass flowing out of the front end of the plurality of nozzles; the bushing is characterized in that: in the front end, the nozzle hole comprises: a pair of first wall portions, each of which has a concave notch facing each other in the short diameter direction of the flat cross section, and a pair of second wall portions facing each other in the long diameter direction of the flat cross section; the long diameter direction of the flat cross section is the extending direction of the cooling area; in the base plate, between adjacent cooling areas, there are spaced-apart walls; The arrangement includes: a first nozzle row, which is formed by arranging the plurality of nozzles at predetermined intervals along the extension direction of the cooling area, and a second nozzle row, which is formed by arranging the plurality of nozzles at predetermined intervals along the extension direction of the cooling area; the plurality of nozzles of the first nozzle row are arranged in such a way that each of the notches provided on the pair of first walls in the first nozzle row faces the cooling area; wherein, for the plurality of nozzles included in the first nozzle row, the notch on one side faces the cooling member directly, and the notch on the other side faces the cooling member through the gap area between the nozzles of the second nozzle row. The liner as described in claim 1, wherein the plurality of nozzles of the second nozzle row are arranged so that each of the notches provided in the pair of first wall portions in the second nozzle row faces the cooling area. A liner as described in claim 1 or 2, wherein the spacing between the plurality of nozzles in the first nozzle row is narrower than the opening width of the notch, and the spacing between the plurality of nozzles in the second nozzle row is narrower than the opening width of the notch. A method for manufacturing a glass fiber with a special profile uses the liner described in claim 1 or 2 to manufacture the glass fiber with a special profile. A method for manufacturing a glass fiber with a special profile uses the liner described in claim 3 to manufacture the glass fiber with a special profile. The method for manufacturing a glass fiber with an irregular cross section as described in claim 4, wherein the molten glass is E glass. The method for producing a glass fiber with an irregular cross section as described in claim 5, wherein the molten glass is E glass. The method for producing a glass fiber with a special cross-section as described in claim 4, wherein the molten glass has a viscosity of 10 ^2.0 to 10 ^3.5 dPa.s at the forming temperature. The method for producing a glass fiber with a special cross-section as described in claim 5, wherein the molten glass has a viscosity of 10 ^2.0 to 10 ^3.5 dPa.s at the forming temperature. The method for producing a glass fiber with a special cross-section as described in claim 6, wherein the molten glass has a viscosity of 10 ^2.0 to 10 ^3.5 dPa.s at the forming temperature.

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