Bushing, glass fiber manufacturing apparatus, and glass fiber manufacturing method

Abstract

To stably manufacture many glass fibers of an optional shape.SOLUTION: A bushing includes: a base plate which has a plurality of cooling zones extending in one specific direction and where a cooling member is arranged and configured so as to cool molten glass; a plurality of first nozzles that are provided at the base plate and arranged in a first zone being a zone along the cooling zone; and a plurality of second nozzles that are provided at the base plate and arranged in a second zone being a zone along the cooling zone. An average distance between the cooling zone and the first zone is shorter than an average distance between the cooling zone and the second zone. An average length of the first nozzles is shorter than an average length of the second nozzles.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to improvements in glass fiber manufacturing technology. [Background technology]

[0002] Circular cross-section glass fibers, which have a perfectly circular cross-section, and irregular cross-section glass fibers, which have non-circular cross-sections such as oval or elliptical flat cross-sections, are used in a variety of fields because they can achieve a high reinforcing effect when mixed with resin to form a composite.

[0003] This type of glass fiber is generally produced by cooling molten glass while drawing it out from a nozzle of a bushing. In this case, the cross-sectional shape of the produced glass fiber depends on the shape of the nozzle hole at the tip of the nozzle as well as the cooling state of the molten glass.

[0004] For example, even if a nozzle having a flat nozzle hole is used to produce a modified cross-section glass fiber, 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 formed to be round due to surface tension just below the tip of the nozzle, making it impossible to produce a desired modified cross-section glass fiber. Also, even when producing a circular cross-section glass fiber, breakage of the glass fiber can be suppressed by appropriately cooling the molten glass.

[0005] Therefore, for example, in the glass fiber manufacturing device of Patent Document 1, the inner layer material has a thermal conductivity of 100 W·m as a cooling member for molten glass. -1 ·k -1 The hollow elongated body and / or solid elongated body are made of the above materials, and the outermost layer material is made of a material containing nickel and / or chromium, thereby making it possible to efficiently cool the molten glass. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-184858 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, there has been a study into increasing the amount of glass fiber drawn from one bushing to improve productivity and produce strands with larger counts, so there has been a study into reducing the number of cooling elements in the bushing and installing nozzles in that area.

[0008] By using the cooling element described in Patent Document 1, the cooling efficiency of the molten glass drawn from the nozzles is improved; however, by reducing the number of cooling elements, the area cooled by each cooling element is expanded, and it may not be possible to adequately cool the molten glass drawn from all the nozzles.

[0009] In view of the above circumstances, an object of the present invention is to stably produce a large number of glass fibers having a desired shape. [Means for solving the problem]

[0010] The bushing of the present invention comprises a base plate extending in a predetermined direction and having a plurality of cooling regions in which cooling members configured to cool molten glass can be placed, a plurality of first nozzles provided on the base plate and arranged in a first region that is a region along the cooling regions, and a plurality of second nozzles provided on the base plate and arranged in a second region that is a region along the cooling regions, wherein the average distance between the cooling regions and the first regions is shorter than the average distance between the cooling regions and the second regions, and the average length of the first nozzles is shorter than the average length of the second nozzles.

[0011] According to this configuration, since multiple rows of nozzle regions are arranged between the cooling members, it is possible to arrange more nozzles than in the past, which improves the productivity of glass fiber and allows a large number of glass fibers to be obtained at one time, making it possible to produce strands with a large count. Furthermore, because the second nozzle, which is located farther from the cooling area, is longer than the first nozzle, variations in the cooling efficiency of the molten glass caused by differences in the distance from the cooling member can be reduced. This allows the viscosity of the molten glass during molding to be properly adjusted, enabling stable molding of glass fibers.

[0012] In the present invention, it is preferable that the nozzle further comprises a plurality of third nozzles provided on the base plate and arranged in a third region that is a region along the cooling region, and that the average distance between the cooling region and the second region is shorter than the average distance between the cooling region and the third region, and that the average length of the second nozzles is shorter than the average length of the third nozzles.

[0013] According to this configuration, even when a larger number of nozzles are arranged, variations in the cooling efficiency of the molten glass can be reduced.

[0014] In the present invention, the first nozzle and the second nozzle preferably have flat nozzle holes at the tip portions from which the molten glass flows out.

[0015] According to this configuration, it is possible to easily produce irregular cross section glass fibers with a large count.

[0016] A glass fiber manufacturing apparatus according to the present invention is characterized by comprising the above-mentioned bushing and a cooling member provided in the cooling region.

[0017] With this configuration, it is possible to obtain the same effects as those of the configurations already described.

[0018] In the present invention, it is preferable that the length of the cooling member from the base plate is longer than the first nozzle and the second nozzle.

[0019] This also makes it possible to efficiently cool the molten glass drawn out from the second nozzle.

[0020] The glass fiber manufacturing method according to the present invention is characterized in that glass fibers are manufactured using the glass fiber manufacturing apparatus. With this configuration, the same effects as those of the configurations already described can be obtained.

[0021] In the present invention, the molten glass is preferably E-glass.

[0022] E-glass is a glass that is resistant to devitrification, which improves the productivity of glass fibers.

[0023] In the present invention, at the forming temperature, the molten glass is 10 2.0 ~10 3·5 It is preferred that the viscosity of the composition is 0.05 dPa·s.

[0024] 10 3·5 If the viscosity is 10 dPa·s or less, the viscosity of the molten glass will not be too high, and the moldability of the glass fiber can be maintained good. 2.0 If the viscosity is dPa·s or higher, the viscosity of the molten glass will not be too low, and therefore, when producing modified cross-section glass fibers, the force that causes the molten glass to return to a circular cross section due to surface tension is weakened, and the aspect ratio (longer diameter dimension / minor diameter dimension) of the glass fiber can be increased. [Effects of the Invention]

[0025] According to the present invention, glass fibers having a desired shape can be produced in large quantities and stably. [Brief explanation of the drawings]

[0026] [Figure 1]FIG. 1 is a cross-sectional view showing a glass fiber manufacturing apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view showing the periphery of the nozzle of the bushing of FIG. [Figure 3] 3 is an enlarged bottom view of the nozzle and its periphery of the bushing of FIG. 1. FIG. [Figure 4] FIG. 4 is an enlarged bottom view showing the periphery of the nozzle of the bushing of the glass fiber manufacturing apparatus according to the second embodiment of the present invention. [Figure 5] FIG. 5 is an enlarged cross-sectional view showing the periphery of a nozzle of a bushing of a glass fiber manufacturing apparatus according to a third embodiment of the present invention. [Figure 6] FIG. 6 is an enlarged bottom view showing the periphery of a nozzle of a bushing of a glass fiber manufacturing apparatus according to a third embodiment of the present invention. [Figure 7] FIG. 7 is an enlarged cross-sectional view showing the periphery of a nozzle of a bushing of a glass fiber manufacturing apparatus according to a fourth embodiment of the present invention. [Figure 8] FIG. 8 is an enlarged bottom view showing the periphery of a nozzle of a bushing of a glass fiber manufacturing apparatus according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Preferred embodiments will be described below. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. In addition, in each drawing, components having substantially the same functions may be referred to by the same reference numerals.

[0028] (First embodiment of glass fiber manufacturing apparatus and manufacturing method) As shown in Fig. 1, a glass fiber manufacturing apparatus 10 according to this embodiment is an apparatus for manufacturing a glass fiber having a circular cross section, and includes a glass melting furnace 1, a forehearth 2 connected to the glass melting furnace 1, and a feeder 3 connected to the forehearth 2. In the Cartesian coordinate system consisting of XYZ shown in Fig. 1, the X and Y directions are horizontal directions, and the Z direction is vertical (the same applies hereinafter).

[0029] Molten glass G is supplied from a glass melting furnace 1 through a forehearth 2 to a feeder 3 and stored in the feeder 3. While FIG. 1 shows an example in which one glass melting furnace 1 is connected to one feeder 3, a plurality of feeders 3 may be connected to the glass melting furnace 1. In addition, a fining furnace may be provided between the glass melting furnace 1 and the forehearth 2.

[0030] In this embodiment, the molten glass G is made of E glass, but it may be made of other glass materials such as D glass, S glass, AR glass, C glass, etc.

[0031] A bushing 4 is disposed at the bottom of the feeder 3. The bushing 4 is attached to the feeder 3 via a bushing block or the like. As shown in FIG. 2, the bottom of the bushing 4 is formed by a base plate 41, and a plurality of nozzles 5 are provided on the base plate 41. The base plate 41 is also provided with a plurality of cooling regions S that extend in the Y direction, which is a predetermined direction, and in which cooling pipes 6 can be placed. The cooling regions S are provided with cooling pipes 6 as cooling members.

[0032] The molten glass G stored in the feeder 3 is drawn downward from a plurality of nozzles 5 provided on the base plate 41 of the bushing 4, and the glass fiber (monofilament) Gm is produced. At this time, the viscosity of the molten glass G at the forming temperature is 10 2.0 ~10 3·5 dPa·s (preferably 10 2.5 ~10 3·3The viscosity of the molten glass G at the forming temperature is set within the range of 0.1 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 it flows into the nozzle 5. A sizing agent is applied to the surface of the glass fibers 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 fibers Gm to be spun; the greater the number of glass fibers Gm, the greater the count of the strand Gs. The spun strand Gs is wound as a fiber bundle Gr on a collet 7 of a winding device. The strand Gs is cut to a predetermined length, for example, about 1 to 20 mm, and used as chopped strands.

[0033] At least a portion of the glass melting furnace 1, forehearth 2, feeder 3, bushing 4, nozzle 5 and cooling pipe 6 is made of platinum or a platinum alloy (for example, a platinum-rhodium alloy), which is an expensive material.

[0034] 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 bushing 4 may be heated by electrical heating or the like.

[0035] 2 and 3, the nozzle 5 includes a nozzle wall 51 and circular nozzle holes 52 defined by the nozzle wall. The nozzle wall 51 has a thickness of 0.1 to 10 mm, and the nozzle holes 52 have a diameter in the range of 0.5 to 15 mm. The nozzle holes 5 are arranged at equal intervals along the X and Y directions. The intervals between the nozzle holes 52 are, for example, approximately 1 to 20 mm.

[0036] 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, a strand Gs with a large count can be obtained. It is preferable that 1,500 or more nozzles 5 are arranged on the base plate 41.

[0037] The cooling pipes 6 are configured to provide cooling by circulating cooling water F as a fluid therethrough. The cooling pipes 6 are plate-shaped, and a plurality of cooling pipes 6 are arranged with their plate surfaces aligned in a fixed direction (Y direction). In this embodiment, the cooling pipes 6 are provided separately from the cooling region S of the base plate 41, but they may be provided integrally with the bottom of the bushing 4. The cooling pipes 6 may also be cylindrical. The height position of the cooling pipes 6 can be adjusted appropriately depending on the cooling conditions of the molten glass G. For example, the cooling pipes 6 may be arranged above the tip of the nozzle 5 so as not to directly face the molten glass G dispensed from the nozzle 5, or may be arranged to straddle both the nozzle 5 and the molten glass G dispensed from the nozzle 5. The cooling member is not limited to the cooling pipes 6, and may be a cooling fin that induces airflow to provide cooling.

[0038] The base plate 41 has a plurality of cooling regions S extending in the Y direction in which the cooling pipes 6 are arranged. The cooling regions S are arranged at predetermined intervals in the X direction. The cooling regions S are flat so that the cooling pipes 6 can be arranged therein. A plurality of nozzles 5 are arranged between the cooling regions S.

[0039] Between the cooling regions S, there are a first region L1 and a second region L2, from the side closest to the cooling region S. The first region L1 and the second region L2 are provided with the same number of nozzles 5 (first nozzles 5a in the first region L1, and second nozzles 5b in the second region L2). The first nozzles 5a are formed by nozzle walls 51a, and the second nozzles 5b are formed by nozzle walls 51b. The length H1 of the first nozzles 5a is shorter than the length H2 of the second nozzles 5b.

[0040] The molten glass G drawn from the first nozzle 51a, which is closer to the cooling pipe 6, is more easily cooled by the cooling pipe 6. On the other hand, the molten glass G drawn from the second nozzle 51b, which is farther from the cooling pipe 6, is less easily cooled by the cooling pipe 6. After extensive research, the inventors of the present invention have found that cooling variations can be suppressed by lowering the temperature of the molten glass G drawn from the second nozzle 51b in advance. After further research, the inventors of the present invention have found that the longer the time that the molten glass G flows through the nozzle hole 51, the lower the temperature of the molten glass G. Therefore, by setting the relationship of the lengths of the nozzles 5 as described above, it is possible to reduce variations in cooling efficiency.

[0041] Therefore, it is not necessary to arrange the cooling pipes 6 next to all of the nozzles 51 , and as a result, it becomes possible to arrange more nozzles 5 on the base plate 41 .

[0042] By setting the ratio (H2 / H1) of the length H1 of the first nozzle 5a to the length H2 of the second nozzle 5b to 1.1 to 2.0, the manufacturing cost of the nozzle 5 (amount of platinum used) can be reduced while reducing variations in cooling.

[0043] Furthermore, the length H3 of the cooling pipe 6 from the base plate 41 is longer than the length H1 of the first nozzle 5a and the length H2 of the second nozzle 5b. In this way, the molten glass G drawn out from the first nozzle 5a and the second nozzle 5b can be efficiently cooled by the cooling pipe 6.

[0044] (Second embodiment of glass fiber manufacturing apparatus and manufacturing method) The glass fiber manufacturing apparatus according to the second embodiment will be described only in terms of the differences from the glass fiber manufacturing apparatus 10 according to the first embodiment.

[0045] As shown in FIG. 4, the nozzles 5 are arranged on the base plate 42 of the bushing 14 in a different arrangement from the base plate 41 of the first embodiment. The nozzles 5 are arranged in a staggered pattern. By arranging the nozzles 5 in this manner, the second nozzles 5b1 arranged in the second region L2 are cooled more efficiently by the cooling pipes 6. In the first embodiment, the second nozzles 5b1 are blocked by the first nozzles 5a1, which may slightly reduce the cooling efficiency of the second nozzles 5b1. In contrast, in the present embodiment, the second nozzles 5b1 are not blocked by the first nozzles 5a1, and are therefore cooled more efficiently.

[0046] (Third embodiment of glass fiber manufacturing apparatus and manufacturing method) The glass fiber manufacturing apparatus according to the third embodiment will be described only with respect to the differences from the glass fiber manufacturing apparatus 10 according to the first embodiment.

[0047] As shown in FIG. 6, the nozzles 5 are arranged on the base plate 43 of the bushing 24 in a different arrangement from that of the base plate 41 of the first embodiment. Between the cooling regions S, a first region L1, a second region L2, and a third region L3 are provided, from the side closest to the cooling region S. The first region L1, the second region L2, and the third region L3 each have the same number of nozzles 5 (a first nozzle 5a in the first region L1, a second nozzle 5b in the second region L2, and a third nozzle 5c in the third region L3). The first nozzle 5a is formed by a nozzle wall 51a, the second nozzle 5b is formed by a nozzle wall 51b, and the third nozzle 5c is formed by a nozzle wall 51c. As shown in FIG. 5, the length H1 of the first nozzle 5a is shorter than the length H2 of the second nozzle 5b, and the length H2 of the second nozzle 5b is shorter than the length H4 of the third nozzle 5c.

[0048] In this way, by increasing the length of the nozzle 5 with increasing distance from the cooling region S, it is possible to reduce variations in the cooling of the molten glass G drawn out from the nozzle 5.

[0049] The length H3 of the cooling pipe 6 from the base plate 43 is longer than the length H1 of the first nozzle 5a, the length H2 of the second nozzle 5b, and the length H4 of the third nozzle 5c. In this way, the molten glass G drawn out from the first nozzle 5a, the second nozzle 5b, and the third nozzle 5c can be efficiently cooled by the cooling pipe 6.

[0050] (Fourth embodiment of glass fiber manufacturing apparatus and manufacturing method) The glass fiber manufacturing apparatus according to the fourth embodiment will be described only with respect to the differences from the glass fiber manufacturing apparatus 10 according to the first embodiment.

[0051] 7 and 8, in the base plate 44 of the bushing 34, a plurality of nozzle regions L4, L5 are arranged in parallel at intervals in the X direction between adjacent cooling regions S. The nozzle 5 has a flat (elliptical in this embodiment) nozzle hole 53. 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. The cross-sectional shape of the nozzle hole 53 may be an ellipse or other shape other than an ellipse.

[0052] Between the cooling regions S, there are a first region L4 and a second region L5, from the side closest to the cooling region S. The first region L4 and the second region L5 are provided with the same number of nozzles 5 (first nozzles 5d in the first region L4 and second nozzles 5e in the second region L5). The first nozzles 5d are formed by nozzle walls 51d, and the second nozzles 5e are formed by nozzle walls 51e. The length H5 of the first nozzles 5d is shorter than the length H6 of the second nozzles 5e.

[0053] A bushing 34 having a flat nozzle hole 53 (elliptical in this embodiment) is used to produce irregular cross-section glass fibers. Even when molten glass G is drawn through a nozzle hole 53 of this shape, the cross section of the glass fiber tends to become perfectly circular due to surface tension. For this reason, it has been necessary to increase the number of cooling members 6 in the past. However, by setting the length relationship of the nozzles 5 as described above, the second nozzle 5e in the second region L5 can also be efficiently cooled, thereby reducing the number of cooling members 6.

[0054] By setting the ratio (H6 / H5) of the length H5 of the first nozzle 5d to the length H6 of the second nozzle 5e to be 1.1 to 2.0, the manufacturing cost of the nozzle 5 (amount of platinum used) can be reduced while reducing variations in cooling.

[0055] Furthermore, the length H7 of the cooling pipe 6 from the base plate 44 is longer than the length H5 of the first nozzle 5d and the length H6 of the second nozzle 5e. In this way, the molten glass G drawn out from the first nozzle 5d and the second nozzle 5e can be efficiently cooled by the cooling pipe 6.

[0056] The number of nozzles 5 included in the first region L4 and the second region L5 is preferably 10 to 100. The total number of nozzles 5 arranged on the base plate 44 is preferably 400 to 4000.

[0057] According to this embodiment in which glass fibers are produced as described above, the following effects can be obtained.

[0058] This embodiment includes a base plate having a plurality of cooling regions extending in a predetermined direction and capable of arranging cooling members configured to cool molten glass, a plurality of first nozzles provided on the base plate and arranged in a first region that is a region along the cooling regions, and a plurality of second nozzles provided on the base plate and arranged in a second region that is a region along the cooling regions, wherein the average distance between the cooling regions and the first regions is shorter than the average distance between the cooling regions and the second regions, and the average length of the first nozzles is shorter than the average length of the second nozzles. By setting the length relationship between the first nozzles and the second nozzles in this way, it is possible to stably produce a large number of glass fibers having a desired shape.

[0059] The method for producing glass fibers according to the embodiment of the present invention has been described above, but the present invention is not limited to this, and various variations are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0060] 1: Glass melting furnace, 4,14,24,34:Bushings 41, 42, 43, 44: Base plate 5: Nozzle 51: Nozzle wall 52, 53: Nozzle holes 6: Cooling pipe 10: Glass fiber manufacturing equipment S: cooling area, L1, L4: First region L2, L5: Second area L3: The third region

Claims

1. a base plate extending in a predetermined direction and including a plurality of cooling regions in which cooling members configured to be able to cool the molten glass can be arranged; a plurality of first nozzles provided on the base plate and arranged in a first region that is a region along the cooling region; a plurality of second nozzles provided on the base plate and arranged in a second region that is a region along the cooling region; A bushing comprising: the first region and the second region are formed between two adjacent cooling regions; an average distance between the cooling region and the first region is shorter than an average distance between the cooling region and the second region; A bushing wherein the average length of the first nozzles is shorter than the average length of the second nozzles.

2. The cooling device further includes a plurality of third nozzles provided on the base plate and arranged in a third region that is a region along the cooling region, the third region is formed between two adjacent cooling regions; an average distance between the cooling region and the second region is shorter than an average distance between the cooling region and the third region; 2. The bushing of claim 1, wherein the average length of the second nozzles is less than the average length of the third nozzles.

3. The bushing according to claim 1 or 2, wherein the first nozzle and the second nozzle each have a flat nozzle hole at a tip end portion through which the molten glass flows.

4. A bushing according to any one of claims 1 to 3; a cooling member provided in the cooling region.

5. 5. The glass fiber manufacturing apparatus according to claim 4, wherein the length of the cooling member from the base plate is longer than the first nozzle and the second nozzle.

6. A method for producing glass fibers using the glass fiber production apparatus according to claim 4 or 5.

7. 7. The method for producing glass fibers according to claim 6, wherein the molten glass is E-glass.

8. At the forming temperature, the molten glass ２．０ ~10 ３．５ 8. The method for producing glass fibers according to claim 6, wherein the glass fiber has a viscosity of 100 dPa·s.

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