Bushing and method for manufacturing glass fiber

Abstract

The present invention aims to provide a drain plate capable of stably drawing molten glass from a nozzle provided on a miniaturized substrate, and a method for manufacturing glass fiber. The drain plate is constructed in a manner that satisfies the following equations (1) to (6) under the following conditions: for each of the first nozzle (N1) and the second nozzle (N2) of the drain plate (11), the inner diameter [mm] of the nozzle hole is D1, the flow path length [mm] of the nozzle is Lt, and the cross-sectional area [mm] of the nozzle hole is 2 ] is A1, the cross-sectional area of ​​the nozzle wall [mm 2 ] is A2, the spacing dimension [mm] between the centers of adjacent first nozzles and the spacing dimension [mm] between the centers of adjacent second nozzles is L1, and the spacing dimension [mm] between the centers of adjacent first and second nozzles is L2. y1≦Y≦y2···(1)y1=4 / 3×X+3···(2)y2=4 / 3×X+8···(3)X=D1 4 / Lt···(4)Y=A3‑(A1+A2)···(5)A3=L1×L2···(6)

Description

Technical Field

[0001] The invention relates to a method for manufacturing a bushing and glass fiber. Background Art

[0002] As disclosed in Patent Document 1, a bushing including a base plate and a plurality of nozzles provided on the bottom surface of the base plate is used for the production of glass fibers.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-231926 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the above-mentioned drain plate, the substrate is miniaturized by arranging adjacent nozzles closer to each other from the perspective of reducing the material consumption of the substrate. However, in the drain plate miniaturized as above, the molten glass flowing out of the nozzles is likely to adhere to the space between the adjacent nozzles. If the molten glass adheres to the space between the adjacent nozzles, it is difficult to stably draw the molten glass from the nozzles, and for example, the glass filaments are likely to break.

[0008] An object of the present invention is to provide a bushing capable of stably drawing out molten glass from a nozzle provided on a miniaturized substrate, and a method for producing glass fibers.

[0009] Means for solving problems

[0010] A leak plate for solving the above-mentioned problem comprises a substrate and a nozzle group arranged on the bottom surface of the substrate, wherein the nozzle group comprises a first nozzle column formed by arranging a plurality of first nozzles, and a second nozzle column formed by arranging a plurality of second nozzles and arranged adjacent to the first nozzle column, and the leak plate is constructed in such a way that the following equations (1) to (6) are satisfied under the following conditions: in each of the first nozzle and the second nozzle, the inner diameter [mm] of the nozzle hole is D1, the flow path length [mm] of the nozzle is Lt, and the cross-sectional area [mm] of the nozzle hole is 2 ] is A1,

[0011] Nozzle wall cross-sectional area [mm 2 ] is A2; the spacing dimension [mm] between the centers of adjacent first nozzles in the above-mentioned first nozzle column and the spacing dimension [mm] between the centers of adjacent second nozzles in the above-mentioned second nozzle column are L1; the spacing dimension [mm] between the center of the column width direction of the above-mentioned first nozzle column and the center of the column width direction of the above-mentioned second nozzle column is L2.

[0012] y1≦Y≦y2···(1)

[0013] y1=4 / 3×X+3···(2)

[0014] y2=4 / 3×X+8···(3)

[0015] X=D1 4 / Lt···(4)

[0016] Y=A3-(A1+A2)···(5)

[0017] A3=L1×L2···(6)

[0018] According to this configuration, since Y is more than y1, the space around the nozzle can be appropriately ensured corresponding to the outflow rate of the molten glass flowing out of the nozzle. Thus, the molten glass flowing out of the nozzle can be suppressed from adhering to adjacent nozzles, etc. In addition, since Y is less than y2, the space around the nozzle will not become too wide relative to the outflow rate of the molten glass flowing out of the nozzle, and therefore, the manufacturing cost of the leak plate can be suppressed to increase.

[0019] The bushing is preferably configured to further satisfy the following formula (7).

[0020] 0.2≦X≦3.0···(7)

[0021] According to this configuration, the molten glass can be drawn out from the nozzle more stably.

[0022] In the above-mentioned leak plate, the average value of the arithmetic mean roughness Ra of the inner peripheral surface of the nozzle hole of the above-mentioned first nozzle and the above-mentioned second nozzle is preferably less than 2μm. According to this structure, the outflow speed of the molten glass flowing out of the nozzle can be made more uniform. Thereby, the molten glass flowing out of the nozzle can be further suppressed from adhering to the adjacent nozzles.

[0023] The glass fiber manufacturing method comprises supplying molten glass to a leak plate, drawing out a plurality of glass filaments from the leak plate, and then bundling the plurality of glass filaments to manufacture glass fibers, wherein the leak plate comprises a substrate and a nozzle group arranged on the bottom surface of the substrate, the nozzle group comprising: a first nozzle column formed by arranging a plurality of first nozzles; and a second nozzle column formed by arranging a plurality of second nozzles and arranged adjacent to the first nozzle column, wherein the leak plate satisfies the above-mentioned formulas (1) to (6) under the following conditions: in each of the first nozzle and the second nozzle, the inner diameter [mm] of the nozzle hole is D1, the flow path length [mm] of the nozzle is Lt, and the cross-sectional area [mm] of the nozzle hole is 2 ] is A1, the cross-sectional area of ​​the nozzle wall [mm2 ] is A2; the spacing dimension [mm] between the centers of adjacent first nozzles in the above-mentioned first nozzle row and the spacing dimension [mm] between the centers of adjacent second nozzles in the above-mentioned second nozzle row

[0024] [mm] is L1; and the distance [mm] between the center of the first nozzle row in the row width direction and the center of the second nozzle row in the row width direction is L2.

[0025] Effects of the Invention

[0026] According to the present invention, molten glass can be stably drawn out from a nozzle provided on a miniaturized substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram which shows the manufacturing apparatus of the glass fiber in embodiment.

[0028] Figure 2 is a bottom view showing a portion of the bushing.

[0029] Figure 3 It is along Figure 2 Partial cross-sectional view of line 3-3.

[0030] Figure 4 It is a diagram showing the relationship between the parameters related to the nozzle size and the parameters related to the nozzle arrangement. DETAILED DESCRIPTION

[0031] Hereinafter, one embodiment of a bushing and a method for producing glass fiber will be described with reference to the drawings.

[0032] like Figure 1 As shown, the leak plate 11 is used for the manufacture of glass fibers (glass strands GS). The manufacturing device of the glass fibers comprises the leak plate 11, an applicator 12 for applying a bundling agent to a large number of glass filaments GF drawn out from the leak plate 11; and a buncher 13 for bundling a large number of glass filaments GF coated with the bundling agent. By bundling a large number of glass filaments GF using the buncher 13, glass strands GS are obtained. The manufacturing device of the glass fibers comprises a collet 14 for winding up the glass strands GS, and a yarn cake CA is obtained by winding the glass strands GS around the collet 14. In addition, although not shown in the figure, the manufacturing device of the glass fibers comprises a traverse for reciprocating the glass strands GS.

[0033] The drain plate 11 includes a drain plate body 11a for supplying molten glass MG and a substrate 11b provided at the bottom of the drain plate body 11a. Although not shown in the figure, the drain plate body 11a includes a supply port for supplying molten glass MG, a mesh screen for suppressing accumulation of foreign matter on the substrate 11b, and a terminal for resistance heating.

[0034] The bushing 11 includes a nozzle group provided on the bottom surface 11b1 of the substrate 11b. Molten glass MG is supplied to each nozzle N, and glass filaments GF are drawn out from each nozzle N. The number of nozzles is preferably 800 to 10,000, more preferably 2,000 to 8,000. In the drawings, the nozzle group of the bushing 11 is simplified.

[0035] like Figure 2 As shown, the nozzle group of the drain plate 11 includes a first nozzle row R1 formed by arranging a plurality of first nozzles N1, and a second nozzle row R2 formed by arranging a plurality of second nozzles N2. The second nozzle row R2 is arranged adjacent to the first nozzle row R1. In detail, the arrangement direction of the plurality of first nozzles N1 and the plurality of second nozzles N2 is Figure 2 The first nozzle array R1 and the second nozzle array R2 are in the horizontal direction along the Y axis. Figure 2 The layers are arranged adjacent to each other in a horizontal direction along the X-axis direction which is orthogonal to the Y-axis direction.

[0036] like Figure 2 and Figure 3 As shown, for the first nozzle N1 and the second nozzle N2, the inner diameter of the nozzle hole [mm] is represented by D1, the flow path length of the nozzle [mm] is represented by Lt, and the cross-sectional area of ​​the nozzle hole [mm 2 ] is represented by A1, and the cross-sectional area of ​​the nozzle wall [mm 2 ] is represented by A2. The first nozzle N1 and the second nozzle N2 have Figure 2 and Figure 3 A flow path extending in the vertical direction along the Z-axis direction.

[0037] like Figure 3 As shown, the nozzle flow path length Lt is the length from the upper surface 11b2 of the substrate 11b to the front end of the nozzle N. That is, the nozzle flow path length Lt [mm] is the sum of the thickness dimension Lt1 [mm] of the substrate 11b and the length dimension Lt2 [mm] from the bottom surface 11b1 of the substrate 11b to the front end of the nozzle N. Figure 2 As shown in the dot pattern, the cross-sectional area of ​​the nozzle hole A1 [mm 2 ] and the cross-sectional area of ​​the nozzle wall A2[mm 2] is the cross-sectional area at the cross section of the nozzle N. In addition, in the present embodiment, the size of the cross-sectional area A1 of the nozzle hole is constant throughout the entire flow path length Lt of each nozzle N, and the size of the cross-sectional area A2 of the nozzle wall is constant throughout the entire length of each nozzle N. In addition, the cross-sectional shape of the nozzle hole is circular, and the glass filament GF having a circular cross section is drawn out from the nozzle hole.

[0038] The bushing 11 is configured to satisfy the following formulas (1) to (6).

[0039] y1≦Y≦y2···(1)

[0040] y1=4 / 3×X+3···(2)

[0041] y2=4 / 3×X+8···(3)

[0042] X=D1 4 / Lt···(4)

[0043] Y=A3-(A1+A2)···(5)

[0044] A3=L1×L2···(6)

[0045] Among them, L1 represents the spacing dimension [mm] between the centers of the adjacent first nozzles N1 in the first nozzle row R1, and the spacing dimension [mm] between the centers of the adjacent second nozzles N2 in the second nozzle row R2. In addition, L2 represents the spacing dimension [mm] between the center of the first nozzle row R1 in the row width direction and the center of the second nozzle row R2 in the row width direction. In other words, L2 represents the spacing dimension [mm] between the centers of one of the first nozzles N1 and the second nozzle N2 located closest to it, that is, the spacing dimension [mm] between the centers of the adjacent first nozzle N1 and second nozzle N2. In addition, a straight line passing through the center of the first nozzle row R1 in the row width direction is parallel to a straight line passing through the center of the second nozzle row R2 in the row width direction. The row width direction of the first nozzle row R1 is parallel to the bottom surface 11b1 of the substrate 11b.

[0046] A direction parallel to and perpendicular to the arrangement direction of the first nozzles N1, for example Figure 2 and Figure 3 The width direction of the second nozzle array R2 is parallel to the bottom surface 11b1 of the substrate 11b and is orthogonal to the arrangement direction of the second nozzles N2. Figure 2 and Figure 3 The X-axis direction is consistent.

[0047] The above formula (4) is a relational expression for obtaining a numerical value representing the degree of the outflow speed of the molten glass MG flowing out of the nozzle N. The larger the inner diameter D1 of the nozzle hole, the faster the outflow speed of the molten glass MG. In addition, the shorter the flow path length Lt of the nozzle, the faster the outflow speed of the molten glass MG.

[0048] The above equation (5) is a relational expression for obtaining a value representing the size of the space around one nozzle N. In detail, the above equation (6) can be used to obtain Figure 2 The arrangement area A3 of each nozzle shown in a spot pattern is the area formed by one nozzle N and the surrounding space of the nozzle N when viewed from above the drain plate 11. In the above formula (5), the area of ​​the surrounding space of one nozzle N can be calculated by subtracting the cross-sectional area A1 of the nozzle hole and the cross-sectional area A2 of the nozzle wall from the arrangement area A3 of the nozzle.

[0049] The inner diameter D1 [mm] of the nozzle hole is preferably within the range of 0.5 mm to 3.0 mm, and more preferably within the range of 0.8 mm to 2.0 mm. The flow path length Lt [mm] of the nozzle is preferably within the range of 1.5 mm to 8.0 mm, and more preferably within the range of 2.5 mm to 6.0 mm. The cross-sectional area A1 [mm 2 ] preferably 0.2 mm 2 Above and 7.0mm 2 The following range is preferred, with 0.5 mm being more preferred. 2 Above and 5.0mm 2 The cross-sectional area of ​​the nozzle wall A2 [mm 2 ]Preferably 0.6 mm 2 Above and 4.9mm 2 The following range is preferred, with 0.8 mm being more preferred. 2 Above and 3.5mm 2 Within the following range.

[0050] From the viewpoint of more stably drawing out the molten glass MG from the nozzle N, for example, the bushing 11 is preferably configured to further satisfy the following formula (7).

[0051] 0.2≦X≦3.0···(7)

[0052] The average value of the arithmetic mean roughness Ra of the inner peripheral surface Ns of the nozzle holes of the first nozzle N1 and the second nozzle N2 is preferably 2 μm or less, more preferably 0.1 μm or more, and further preferably within the range of 0.3 μm or more and 1.5 μm or less.

[0053] The average value of the arithmetic mean roughness Ra of the inner circumferential surface Ns of the nozzle hole can be adjusted by the shape of the drill used in the drilling process of the nozzle hole and the vibration of the drill. In addition, the average value of the arithmetic mean roughness Ra of the inner circumferential surface Ns of the nozzle hole can also be adjusted by bringing the drill into contact with the inner circumferential surface Ns of the nozzle hole and performing annealing.

[0054] The average value of the arithmetic mean roughness Ra is the average value of the unused state before the molten glass MG is circulated.

[0055] The average value of the arithmetic mean roughness Ra can be measured as follows.

[0056] First, after a plurality of nozzles N are manufactured under the same manufacturing conditions, a nozzle N to be measured is extracted from the plurality of nozzles N as a sample. Next, the extracted sample is cut along the direction in which the hole axis of the nozzle hole extends (the direction in the bushing 11 as the Z-axis direction). Next, the arithmetic mean roughness Ra of the inner peripheral surface Ns of the nozzle hole is measured along the direction in which the hole axis extends in accordance with JIS B0601:2001.

[0057] In addition, in the measurement of the arithmetic mean roughness Ra, Surfcorder (manufactured by Kosaka Laboratory Co., Ltd., product name: ET4000) was used, and the measurement distance was set to 1 mm. In addition, the arithmetic mean roughness Ra was measured at 6 locations different from each other.

[0058] Next, the average of the arithmetic mean roughness Ra measured at the six locations is calculated and used as the average value of the arithmetic mean roughness Ra of the inner circumferential surface Ns. Nozzles N other than the sample for which the arithmetic mean roughness Ra is measured are considered to have the same average value as the average value of the arithmetic mean roughness Ra in the sample.

[0059] The bushing 11 of this embodiment further includes a plurality of cooling members 15 provided on the bottom surface 11b1 of the substrate 11b. The cooling members 15 cool the molten glass MG drawn out from the nozzle N. Examples of the cooling members 15 include cooling fins and cooling pipes having a flow path for circulating a cooling medium therein.

[0060] Each cooling member 15 has a length direction and is arranged in a manner extending along the first nozzle row R1 and the second nozzle row R2. A plurality of cooling members 15 are arranged at predetermined intervals. In the leak plate 11 of the present embodiment, two nozzle rows consisting of the first nozzle row R1 and the second nozzle row R2 are arranged between adjacent cooling members 15, but three or more nozzle rows may be arranged between adjacent cooling members 15.

[0061] As the material of the drain plate body 11a, the substrate 11b, the nozzle N, and the cooling member 15, for example, a noble metal or a noble metal alloy can be cited. The noble metal is gold, silver, platinum, palladium, rhodium, iridium, ruthenium or osmium. From the perspective of improving durability, the material of the drain plate body 11a, the substrate 11b, the nozzle N, and the cooling member 15 is preferably platinum or a platinum alloy. As the platinum alloy, for example, a platinum-rhodium alloy can be cited.

[0062] Next, a method for producing glass fibers will be described.

[0063] In the method for producing glass fibers, molten glass MG is supplied to the bushing 11 , and after a plurality of glass filaments GF are drawn out from the bushing 11 , the plurality of glass filaments GF are bundled to produce glass strands GS.

[0064] The viscosity of the molten glass MG at the molding temperature for molding the glass filaments GF is preferably 10 2.0 ~10 3.5 dPa·s, more preferably 10 2.5 ~10 3.3 Here, the viscosity of the molten glass MG refers to the viscosity of the molten glass at the position where it flows into the nozzle N.

[0065] As the form of glass fiber, for example, a fiber cake CA obtained by winding glass strands GS can be cited. Glass strands GS can be used as, for example, chopped fibers cut into a predetermined length, milled fibers, coarse sand, yarn, mat, cloth, tape, or braided cloth, etc. As the use of glass fiber, for example, vehicle use, electronic material use, building material use, civil engineering use, aircraft-related use, shipbuilding use, logistics use, industrial machinery use, and daily necessities use can be cited.

[0066] Next, the operation and effects of this embodiment will be described.

[0067] (1) The faster the outflow speed of the molten glass MG flowing out of the nozzle N is, and the narrower the space around the nozzle N is, the easier it is for the molten glass MG flowing out of the nozzle N to adhere to the adjacent nozzles N. Here, the bushing 11 of the present embodiment is configured to satisfy the above-mentioned formulas (1) to (6). That is, in the bushing 11 of the present embodiment, since Y is greater than or equal to y1, the space around the nozzle N can be appropriately ensured corresponding to the outflow speed of the molten glass MG flowing out of the nozzle N. Thus, it is possible to suppress the molten glass MG flowing out of the nozzle N from adhering to the adjacent nozzles N. In addition, in the bushing 11 of the present embodiment, since Y is less than or equal to y2, the space around the nozzle N will not be too wide relative to the outflow speed of the molten glass MG flowing out of the nozzle N, so that the manufacturing cost of the bushing 11 can be suppressed. Therefore, the molten glass MG can be stably drawn out from the nozzle N provided on the miniaturized substrate 11b. Thus, for example, the occurrence of breakage of the glass filament GF can be suppressed.

[0068] (2) It is preferable that the bushing 11 is configured so as to further satisfy the above-mentioned formula (7). In this case, the molten glass MG can be drawn out from the nozzle N more stably.

[0069] (3) In the drain plate 11, the average value of the arithmetic mean roughness Ra of the inner peripheral surface Ns of the nozzle holes of the first nozzle N1 and the second nozzle N2 is preferably 2 μm or less. In this case, the outflow speed of the molten glass MG flowing out of the nozzle N can be made more uniform. As a result, the molten glass MG flowing out of the nozzle N can be further suppressed from adhering to adjacent nozzles N. Therefore, the molten glass MG can be more stably drawn out from the nozzle N provided on the miniaturized substrate 11b.

[0070] (Change Example)

[0071] The above-mentioned embodiment can be implemented by modification as follows. The above-mentioned embodiment and the following modification examples can be implemented by combining with each other within the range of no technical contradiction.

[0072] The cooling member 15 of the bushing 11 may be omitted.

[0073] In the drain plate 11, the inner diameters of the nozzle holes in each of the plurality of first nozzles N1 and the plurality of second nozzles N2 may be the same or different from each other. When the inner diameters of the nozzle holes in each of the nozzles N are different from each other, the average value of the inner diameters of the nozzle holes may be used as the inner diameter D1 [mm] of the nozzle hole in the above formula (4).

[0074] In the bushing 11, when Y in the formula (1) is y2 or less, Y may be y2a or less as shown in the following formula (8), or y2b or less as shown in the following formula (9).

[0075] y2a=4 / 3×X+7···(8)

[0076] y2b=4 / 3×X+5···(9)

[0077] In the drain plate 11, the flow path lengths of the plurality of first nozzles N1 and the plurality of second nozzles N2 may be the same or different from each other. When the flow path lengths of the nozzles N are different from each other, the average value [mm] of the flow path lengths of the nozzles N may be used as Lt in the above formula (4).

[0078] In the drain plate 11, the cross-sectional areas of the nozzle holes in each of the plurality of first nozzles N1 and the plurality of second nozzles N2 may be the same or different from each other. When the cross-sectional areas of the nozzle holes in each of the nozzles N are different from each other, the cross-sectional areas [mm 2 ] is taken as A1 in the above formula (5).

[0079] In the drain plate 11, the cross-sectional areas of the nozzle walls of the plurality of first nozzles N1 and the plurality of second nozzles N2 may be the same or different from each other. When the cross-sectional areas of the nozzle walls of the nozzles N are different from each other, the cross-sectional areas of the nozzle walls [mm 2 ] is taken as A2 in the above formula (5).

[0080] The spacing dimensions between the centers of the first nozzles N1 may be the same or different. When the spacing dimensions between the centers of the first nozzles N1 are different, the average value calculated from the spacing dimension [mm] between the centers of the first nozzles N1 and the spacing dimension [mm] between the centers of the second nozzles N2 may be used as L1 in the above formula (6).

[0081] The spacing dimensions between the centers of the second nozzles N2 may be the same or different. When the spacing dimensions between the centers of the second nozzles N2 are different, the average value calculated from the spacing dimension [mm] between the centers of the second nozzles N2 and the spacing dimension [mm] between the centers of the first nozzles N1 may be used as L1 in the above formula (6).

[0082] The average value of the spacing dimensions between the centers of the first nozzle N1 and the average value of the spacing dimensions between the centers of the second nozzle N2 may be the same as or different from each other. When the average value of the spacing dimensions between the centers of the first nozzle N1 and the average value of the spacing dimensions between the centers of the second nozzle N2 are different from each other, the average value calculated from the spacing dimensions [mm] between the centers of the first nozzle N1 and the spacing dimensions [mm] between the centers of the second nozzle N2 may be used as L1 in the above formula (6).

[0083] In the drain plate 11 of the above-mentioned embodiment, the first nozzle N1 and the second nozzle N2 are arranged in such a manner that the center of the first nozzle N1 and the center of the second nozzle N2 are located on a straight line orthogonal to the arrangement direction of the first nozzle N1 and the second nozzle N2 when the drain plate 11 is viewed from above. The arrangement is not limited to such an arrangement, and the first nozzle N1 and the second nozzle N2 may be arranged in such a manner that either the center of the first nozzle N1 or the center of the second nozzle N2 is located at a position offset from the straight line orthogonal to the arrangement direction of the first nozzle N1 and the second nozzle N2 when the drain plate 11 is viewed from above.

[0084] In the first nozzle array R1 of the drain plate 11 of the above-mentioned embodiment, the first nozzles N1 are arranged so that the centers of the first nozzles N1 are located on a straight line when the drain plate 11 is viewed from above. The arrangement is not limited to this, and in the first nozzle array R1, when the centers of all the first nozzles N1 cannot be located on a straight line, a straight line may be set so that the sum of the distances between the straight line and the centers of the first nozzles N1 is minimized.

[0085] In the second nozzle array R2 of the drain plate 11 of the above-mentioned embodiment, the second nozzles N2 are arranged so that the centers of the second nozzles N2 are located on a straight line when the drain plate 11 is viewed from above. The arrangement is not limited to this, and in the second nozzle array R2, when the centers of all the second nozzles N2 cannot be located on a straight line, a straight line may be set so that the sum of the distances between the straight line and the centers of the second nozzles N2 is minimized.

[0086] In the drain plate 11 of the above embodiment, the straight line passing through the center of the first nozzle row R1 in the row width direction and the straight line passing through the center of the second nozzle row R2 in the row width direction are parallel, but they may not be parallel. However, in the drain plate 11, the straight line passing through the center of the first nozzle row R1 in the row width direction and the straight line passing through the center of the second nozzle row R2 in the row width direction need not intersect. In this case, L2 represents the spacing dimension [mm] between the line passing through the center of the first nozzle row R1 in the row width direction and the line passing through the center of the second nozzle row R2 in the row width direction.

[0087] Next, examples and comparative examples are described.

[0088] (Examples 1 to 50)

[0089] In Examples 1 to 50, glass fibers were produced using a bushing having the values ​​of X and Y shown in Tables 1 and 2. The number of nozzles in the bushing was 100, and the average value of the arithmetic mean roughness Ra of the inner peripheral surface of the nozzle hole was 1.5 μm. The viscosity of the molten glass at the molding temperature for molding the glass filaments was 10 3.0dPa·s, and the speed of molding the glass filaments is within the range of 800 [m / min] to 3000 [m / min].

[0090] (Comparative Examples 1 to 16)

[0091] In Comparative Examples 1 to 16, glass fibers were produced in the same manner as in Examples 1 to 50 except that bushings having the X values ​​and Y values ​​shown in Table 3 were used.

[0092] (Productivity of glass fiber)

[0093] Glass fibers were produced continuously for 30 days using the bushings of Examples 1 to 50 and the bushings of Comparative Examples 1 to 16. The productivity of the glass fibers produced over 30 days was evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 1 to 3.

[0094] When the average number of glass filament breakages is 10 times / day or less: (A) The productivity is high.

[0095] When the average number of glass filament breakages is greater than 10 times / day and is 30 times / day or less: (B) the productivity is slightly low.

[0096] When the average number of glass filament breakages is greater than 30 times / day: (C) productivity is low.

[0097] (Effect of reducing material usage)

[0098] For each example of the leak plate, the case where Y represented by formula (1) is less than y2 is evaluated as having a reduction effect on the amount of substrate material (○), and the case where Y represented by formula (1) is greater than y2 is evaluated as not having a reduction effect on the amount of substrate material (×). The results are shown in Tables 1 to 3.

[0099] [Table 1]

[0100]

[0101] [Table 2]

[0102]

[0103] [Table 3]

[0104]

[0105] Figure 4A graph is shown which plots the X value and the Y value in the leak plate of each example in Tables 1 to 3. In the graph, the leak plates of Examples 1 to 50 are indicated by "○", and the leak plates of Comparative Examples 1 to 16 are indicated by "△". In addition, in the graph, the straight line of the above formula (2) is indicated by a solid line, and the straight line of the above formula (3) is indicated by a dotted line. It can be seen from the graph that the leak plates of Examples 1 to 50 have a structure within the range represented by the above formula (1). On the other hand, it can be seen that the leak plates of Comparative Examples 1 to 16 have a structure outside the range represented by the above formula (1).

[0106] The evaluation results of high productivity of glass fiber were obtained in the leak plates of Examples 1 to 50. On the other hand, the evaluation results of low productivity of glass fiber were obtained in the leak plates of Comparative Examples 2, 3, 6, 8, 10, 12, 13, and 15. In addition, for the leak plates of Comparative Examples 1, 4, 5, 7, 9, 11, 14, and 16, the space around the nozzle was too large relative to the outflow speed of the molten glass flowing out of the nozzle, so the material consumption of the substrate could not be appropriately reduced.

[0107] Explanation of symbols

[0108] 11…Break plate

[0109] 11b…Substrate

[0110] 11b1… bottom

[0111] A1… Cross-sectional area of ​​the nozzle hole

[0112] A2… Cross-sectional area of ​​the nozzle wall

[0113] A3…Nozzle layout area

[0114] CA…Silk cake

[0115] D1…Inner diameter of the nozzle hole

[0116] GF…Glass Filament

[0117] GS…Glass Strand

[0118] Lt…Flow path length of the nozzle

[0119] L1: The distance between the centers of adjacent nozzles in the first nozzle row or the second nozzle row.

[0120] L2: The distance between the centers of the first and second nozzles adjacent to each other

[0121] MG…Molten Glass

[0122] N…Nozzle

[0123] N1…Nozzle 1

[0124] N2…Nozzle 2

[0125] Ns…Inner Surface

[0126] R1…1st nozzle row

[0127] R2…2nd nozzle row

Claims

1. A bushing, comprising a substrate and a nozzle group arranged on the bottom surface of the substrate, wherein: The nozzle assembly comprises: a first nozzle row formed by arranging a plurality of first nozzles; and a second nozzle row formed by arranging a plurality of second nozzles and arranged adjacent to the first nozzle row, The bushing is constructed so as to satisfy the following equations (1) to (6) under the following conditions: In each of the first nozzle and the second nozzle, the inner diameter [mm] of the nozzle hole is D1, the flow path length [mm] of the nozzle is Lt, and the cross-sectional area [mm] of the nozzle hole is 2 ] is A1, the cross-sectional area of ​​the nozzle wall [mm 2 ] is A2, The distance [mm] between the centers of the adjacent first nozzles in the first nozzle row and the distance [mm] between the centers of the adjacent second nozzles in the second nozzle row are L1, The distance [mm] between the center of the first nozzle array in the row width direction and the center of the second nozzle array in the row width direction is L2, Formula (1) to (6): y1≦Y≦y2···(1) y1=4 / 3×X+3···(2) y2=4 / 3×X+8···(3) X=D1 4 / Lt···(4) Y=A3-(A1+A2)···(5) A3=L1×L2···(6).

2. The bushing according to claim 1, further comprising: Formula (7): 0.2≦X≦3.0···(7)。 3. The bushing according to claim 1 or claim 2, wherein: The average value of the arithmetic mean roughness Ra of the inner peripheral surfaces of the nozzle holes of the first nozzle and the second nozzle is 2 μm or less.

4. A method for producing glass fiber, wherein molten glass is supplied to a bushing, a plurality of glass filaments are drawn out from the bushing, and the plurality of glass filaments are bundled to produce glass fiber, wherein: The drain plate comprises a substrate and a nozzle group arranged on the bottom surface of the substrate. The nozzle assembly comprises: a first nozzle row formed by arranging a plurality of first nozzles; and a second nozzle row formed by arranging a plurality of second nozzles and arranged adjacent to the first nozzle row, In the following cases, the drain plate satisfies the following equations (1) to (6): In each of the first nozzle and the second nozzle, the inner diameter [mm] of the nozzle hole is D1, the flow path length [mm] of the nozzle is Lt, and the cross-sectional area [mm] of the nozzle hole is 2 ] is A1, the cross-sectional area of ​​the nozzle wall [mm 2 ] is A2, The distance [mm] between the centers of the adjacent first nozzles in the first nozzle row and the distance [mm] between the centers of the adjacent second nozzles in the second nozzle row are L1, The distance [mm] between the center of the first nozzle array in the row width direction and the center of the second nozzle array in the row width direction is L2, Formula (1) to (6): y1≦Y≦y2···(1) y1=4 / 3×X+3···(2) y2=4 / 3×X+8···(3) X=D1 4 / Lt···(4) Y=A3-(A1+A2)···(5) A3=L1×L2···(6).

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