Bushing and method for manufacturing special-shaped cross-section glass fiber

Abstract

The present invention relates to a leak plate and a method for manufacturing special-shaped cross-section glass fibers, wherein the leak plate comprises: a substrate, comprising a plurality of cooling areas extending in one direction and capable of being configured as cooling components capable of cooling molten glass; and a plurality of nozzles arranged on the substrate, comprising a flat nozzle hole at the front end portion where the molten glass flows out, a pair of first walls opposing each other in the short-diameter direction of the nozzle hole and having concave cutouts, and a pair of second walls opposing each other in the long-diameter direction of the nozzle hole, the leak plate arranges the plurality of nozzles in a manner such that the first walls face the cooling areas, a first nozzle row is arranged between adjacent cooling areas, wherein the plurality of nozzles are arranged at prescribed intervals in the extension direction of the cooling areas, a second nozzle row is arranged at a distance from the first nozzle row and wherein the plurality of nozzles are arranged at prescribed intervals in the extension direction of the cooling areas, and the nozzles of the first nozzle row are arranged in a manner such that the cutouts provided on the pair of first wall portions of the nozzles in the first nozzle row can respectively face the cooling areas.

Description

Technical Field

[0001] The present invention relates to an improvement in the manufacturing technology of special-shaped cross-section glass fibers. Background Art

[0002] Special-shaped glass fibers having a non-circular cross-section, such as a flat shape such as an oblong or elliptical cross-section, can achieve a high reinforcing effect when mixed with a resin to form a composite, and are therefore used in various fields.

[0003] Such irregular cross-section glass fibers are typically produced by cooling molten glass while it is drawn from a nozzle of a bushing. The cross-sectional shape of the produced glass fiber depends on the shape of the nozzle hole at the front end of the nozzle. Therefore, in the case of producing irregular cross-section glass fibers, the nozzle hole at the front end of the nozzle is usually flat.

[0004] However, even when 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 easily rounded due to surface tension just below the nozzle tip, making it impossible to produce the desired deformed cross-section glass fiber.

[0005] Therefore, for example, in the nozzle of patent document 1, a pair of long wall portions opposing each other in the short diameter direction of the flat nozzle hole are provided with concave cutout portions at the front end of the nozzle for outflowing molten glass, and the viscosity of the molten glass is adjusted by cooling through the concave cutout portions.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-226579 Summary of the Invention

[0009] Technical problem that the invention aims to solve

[0010] In recent years, research has been conducted on increasing the number of profiled glass fibers drawn from a single bushing to improve productivity and produce high-count strands. However, as described in Patent Document 1, by placing cooling elements near the two cutouts, the number of nozzles provided on the bushing is reduced, which sometimes fails to fully improve the productivity of profiled glass fibers.

[0011] Furthermore, when cooling members are arranged near the two cutouts to cool the molten glass, the molten glass may be excessively cooled, and thus, it may be impossible to stably form a deformed cross-section glass fiber.

[0012] In view of the above-mentioned actual situation, an object of the present invention is to stably produce a desired modified-cross-section glass fiber.

[0013] Technical means to solve the problem

[0014] The leak plate involved in the present invention comprises: a substrate, the substrate having a plurality of cooling areas, the plurality of cooling areas extending in a predetermined direction and capable of being configured with a cooling component, the cooling component being configured to cool molten glass; and a plurality of nozzles, the plurality of nozzles being arranged on the substrate, and comprising at a front end portion for the molten glass to flow out: a flat nozzle hole, a pair of first walls opposing each other in the short diameter direction of the nozzle hole and having a concave cutout, and a pair of second walls opposing each other in the long diameter direction of the nozzle hole, the leak plate being configured with the plurality of nozzles in a manner such that the first wall portion faces the direction of the cooling area, and between adjacent cooling areas being configured: a first nozzle row, the first nozzle row being configured with the plurality of nozzles at predetermined intervals along the extension direction of the cooling area; and a second nozzle row being spaced apart from the first nozzle row and the plurality of nozzles being arranged at predetermined intervals along the extension direction of the cooling area, the nozzles of the first nozzle row being configured so that the cutouts provided on the pair of first wall portions of the nozzles in the first nozzle row can respectively face the cooling area.

[0015] This structure, with the first and second nozzle rows positioned between the cooling elements, allows for more nozzles to be deployed compared to conventional methods. This improves the productivity of irregular-section glass fibers and enables the production of multiple glass fibers simultaneously, enabling the manufacture of high-count strands.

[0016] Furthermore, one of the nozzles in the first nozzle row directly faces the cooling element, while the other faces the cooling element via the gap between the nozzles in the second nozzle row. This prevents excessive cooling of the molten glass. Consequently, the viscosity of the molten glass during forming can be appropriately adjusted, allowing for the stable formation of special-shaped cross-section glass fibers.

[0017] Furthermore, when the other notch faces only the nozzles of the second nozzle row, the molten glass is not cooled.

[0018] In the present invention, preferably, the nozzles of the second nozzle array are arranged so that the cutouts provided in the pair of first wall portions of the nozzles in the second nozzle array can each be opposed to the cooling region.

[0019] According to such a configuration, even in the molten glass drawn out from the nozzles included in the second nozzle row, the viscosity of the molten glass during molding can be appropriately adjusted, thereby stably forming a deformed cross-section glass fiber.

[0020] In the present invention, preferably, intervals between the plurality of nozzles in the first nozzle array and between the plurality of nozzles in the second nozzle array are narrower than widths of front ends of cutouts of the nozzles.

[0021] According to such a structure, it is possible to reliably suppress the molten glass from being excessively cooled.

[0022] The method for producing a deformed cross-section glass fiber according to the present invention is characterized in that the deformed cross-section glass fiber is produced using the above-mentioned bushing. With such a structure, the same effects as those of the structure described above can be obtained.

[0023] In the present invention, the molten glass is preferably E-glass. Since E-glass is difficult to devitrify, the productivity of the special-shaped cross-section glass fiber is improved.

[0024] In the present invention, preferably, at the forming temperature, the molten glass has 10 2.0 ~10 3.5 dPa·s viscosity. That is, if the viscosity of the molten glass is 10 3·5 dPa·s or less, the viscosity of the molten glass will not become too high, so the formability of the glass fiber can be well maintained. 2.0 If the viscosity of the molten glass is greater than dPa·s, the viscosity of the molten glass will not be too low, so the force of the molten glass to return to a circular cross section due to surface tension is weakened, and the aspect ratio (major axis / minor axis) of the glass fiber can be increased.

[0025] Effects of the Invention

[0026] According to the present invention, desired modified-cross-section glass fibers can be stably produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a cross-sectional view showing an apparatus for producing a deformed-cross-section glass fiber according to one embodiment of the present invention.

[0028] Figure 2 It is shown enlarged Figure 1 Cross-sectional view of the nozzle periphery of the bushing.

[0029] Figure 3 It is shown enlarged Figure 1 Bottom view of the nozzle periphery of the bushing.

[0030] Figure 4 The figures show the nozzle of the bushing according to the embodiment of the present invention, (a) is a side view thereof, (b) is an A1-A1 sectional view of (a), and (c) is a B1-B1 sectional view of (a).

[0031] Figure 5 It is shown enlarged Figure 3 Bottom view of the nozzle periphery of the bushing.

[0032] Figure 6 It is a bottom view showing, in an enlarged manner, the nozzle and the surrounding area of a bushing according to a comparative example.

[0033] Explanation of symbols

[0034] 1: Glass melting furnace

[0035] 4: Leaky plate

[0036] 41: Substrate

[0037] 5: Nozzle

[0038] 51: Long wall portion (first wall portion)

[0039] 52: Short wall portion (second wall portion)

[0040] 53: Nozzle hole

[0041] 54: Incision

[0042] 6: Cooling pipe

[0043] 10: Special-shaped cross-section glass fiber manufacturing device

[0044] G: Molten glass

[0045] Gm: Glass fiber (monofilament)

[0046] Gs: Strands

[0047] S: Cooling area

[0048] L1: First nozzle row

[0049] L2: Second nozzle row

[0050] W: opening width of the cut DETAILED DESCRIPTION

[0051] The following describes preferred embodiments. However, the following embodiments are merely illustrative, and the present invention is not limited thereto. In the accompanying drawings, components having substantially the same function are sometimes referenced by the same reference numerals. Numerical ranges expressed as "to" in this specification refer to ranges that include the values before and after "to" as minimum and maximum values, respectively.

[0052] (One embodiment of a device and method for producing irregular-section glass fibers)

[0053] like Figure 1As shown, the apparatus 10 for producing irregular cross-section glass fibers according to this embodiment 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. Figure 1 In the orthogonal coordinate system composed of XYZ shown, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction (the same applies hereinafter).

[0054] 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. Figure 1 Although one feeder 3 is shown in the figure, a plurality of feeders 3 may be connected to the glass melting furnace 1. In addition, a clarifier furnace may be provided between the glass melting furnace 1 and the forehearth 2.

[0055] In this embodiment, the molten glass G is composed of E glass, but may be made of other glass materials such as D glass, S glass, AR glass, and C glass.

[0056] A leak plate 4 is provided at the bottom of the feeder 3. The leak plate 4 is mounted on the feeder 3 via a leak block or the like. Figure 2 As shown, the bottom of the drain plate 4 is composed of a substrate 41, and a plurality of nozzles 5 are provided on the substrate 41. In addition, a plurality of cooling areas S are provided on the substrate 41, and the plurality of cooling areas S extend along the Y direction as a predetermined direction and can be provided with cooling pipes 6 (see Figure 3 ). In addition, a cooling pipe 6 is provided in the cooling area S as a cooling member.

[0057] 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 to produce glass fibers (monofilaments) Gm. At this time, the viscosity of the molten glass G at the forming temperature is set at 10 2.0 ~10 3·5 dPa·s (preferably 10 2.5 ~10 3·3 dPa·s). It should be noted that 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 fiber Gm using an applicator not shown, and 100 to 10,000 strands are spun into one strand Gs. It should be noted that the number of strands Gs depends on the glass fiber Gm obtained by spinning, and the greater the number of glass fibers Gm, the greater the number of strands Gs. The strands Gs obtained by spinning are wound around the barrel clamp 7 of the winding device as a fiber bundle Gr. The strands Gs are cut into a specified length of, for example, about 1 to 20 mm and used as chopped strands.

[0058] At least a portion of the glass melting furnace 1 , the forehearth 2 , the feeder 3 , the bushing 4 , the nozzle 5 , and the cooling pipe 6 is formed of platinum or a platinum alloy (eg, a platinum-rhodium alloy).

[0059] 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.

[0060] like Figure 2 as well as Figure 3 As shown, the nozzle 5 has a pair of long wall portions (first wall portions) 51 opposing each other in the X direction, a pair of short wall portions (second wall portions) 52 opposing each other in the Y direction, and a flat (in this embodiment, an oblong) nozzle hole 53 defined by the long wall portions 51 and the short wall portions 52. A cutout 54 is provided in each long wall portion 51, and a portion of the nozzle hole 53 communicates with the external space of the nozzle 5 through the cutout 54. In this embodiment, the major diameter direction of the nozzle hole 53 coincides with the Y direction, and the minor diameter direction of the nozzle hole 53 coincides 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, the dimensional relationship between the wall portions 51 and 52 is not particularly limited. In addition, the cross-sectional shape of the nozzle hole 53 may be an elliptical shape or other shape other than an oblong shape.

[0061] like Figure 4 As shown in (a) to (c), the cutouts 54 provided on each long wall portion 51 of the nozzle 5 are trapezoids of the same size. Specifically, in this embodiment, the cutout 54 is an isosceles trapezoidal shape (the upper base is shorter than the lower base) having a center point T1 of the upper base on the center line M1 of the long wall portion 51 and symmetrical with respect to the center line M1. The internal angle θ1 (the internal angle on both sides of the upper base) is, for example, greater than 90° and less than or equal to 160° (preferably 110° to 150°). In addition, in this embodiment, the nozzle hole 53 is a flat oblong shape that is a fixed shape in the Z direction. As shown in FIG. Figure 4 As shown in (c), at the tip of the nozzle 5, the ratio (a / b) of the Y-direction dimension (major diameter dimension) a to the X-direction dimension (minor diameter dimension) b of the nozzle hole 53 is in the range of 1.5 to 20 (preferably 3 to 10).

[0062] This structure can suppress shape deformation caused by the cutout 54 of the nozzle 5, while also ensuring a sufficient opening area for the cutout 54. Consequently, it is possible to stably form glass fibers Gm having a non-circular cross-section, such as a flattened cross-section. In other words, the cross-sectional shape of the produced glass fibers Gm can have a reduced variation.

[0063] The nozzle 5 only needs to have a flat nozzle hole 53 defined by a long wall portion 51 and a short wall portion 52 at the front end portion, and the shape of the base end portion (upper portion) may be the same as or different from the shape of the front end portion of the nozzle 5 .

[0064] It is preferable to arrange 200 to 10,000 nozzles 5 on the substrate 41. By arranging the above number of nozzles 5, a large number of strands Gs can be obtained. In addition, it is preferable to arrange 1,500 or more nozzles 5 on the substrate 41.

[0065] The cooling pipe 6 circulates the cooling water F as a fluid inside it and plays a cooling role. The cooling pipe 6 is a plate-like body, and a plurality of them are arranged in a manner such that their plate surface is along a certain direction (up and down direction). It should be noted that, in the present embodiment, the cooling pipe 6 is integrally provided in the cooling area S of the substrate 41, but may also be provided separately from the bottom of the leak plate 4. In addition, the cooling pipe 6 may also be a circular tubular body. The height position of the cooling pipe 6 may be appropriately adjusted according to the cooling conditions of the molten glass G. For example, the cooling pipe 6 may be arranged at a position above the front end of the nozzle 5 in a manner not directly opposite to the molten glass G drawn from the nozzle 5, or may be arranged in a manner that spans both the nozzle 5 and the molten glass G drawn from the nozzle 5. The cooling component is not limited to the cooling pipe 6, and may also be a cooling fin that guides the air flow to play a cooling role.

[0066] like Figure 3 and Figure 5 As shown, in the substrate 41 of the leak plate 4, between adjacent cooling areas S, a plurality of nozzle rows L1 and L2 are arranged in parallel at intervals in the X direction. Each nozzle row L1 and L2 is formed by arranging a plurality of nozzles 5 with the major diameter direction of the nozzle hole 53 facing the Y direction on the same straight line extending along the Y direction. The cooling pipe 6 is arranged parallel to the nozzle rows L1 and L2 between the adjacent nozzle rows L1 and L2 in the X direction. In addition, in this embodiment, the arrangement positions of the nozzles 5 in the Y direction are different in the nozzle row L1 and the nozzle row L2, but are the same otherwise. Thus, as shown in FIG. Figure 5 As shown, the cooling pipe 6 is opposed to the notch 54a of the nozzle 5 adjacent to the cooling pipe 6, and the molten glass G flowing through the nozzle 5 is cooled by the notch 54a. Specifically, at the tip of the nozzle 5, the molten glass G is rapidly cooled from a temperature of over 1000°C by the cooling pipe 6. In addition, the cooling pipe 6 also has the function of cooling the bushing plate 4 and the nozzle 5, thereby suppressing thermal degradation of the bushing plate 4 and the nozzle 5 and improving their durability.

[0067] Furthermore, the cutout 54b of the nozzle 5 that is not adjacent to the cooling tube 6 also faces the cooling member 6 via the gap between the nozzles 5 included in the adjacent nozzle rows (L2 for the nozzle row adjacent to nozzle row L1, and L1 for the nozzle row adjacent to nozzle row L2). This prevents the molten glass G from being overcooled. Consequently, the viscosity of the molten glass G during forming can be appropriately adjusted, allowing for stable formation of irregular-section glass fibers. Specifically, the molten glass G on the cutout 54a side of the nozzle 5 is rapidly cooled because it is directly opposite the cooling tube 6. However, the molten glass G on the cutout 54b side of the nozzle 5 is cooled more slowly than the molten glass G on the cutout 54a side because it is separated from the cooling tube 6 by a predetermined distance. Consequently, the molten glass G on the cutout 54a side solidifies immediately and is difficult to deform. Meanwhile, the molten glass G on the cutout 54b side can deform to some extent before solidifying. In order to stably form a highly flattened, irregularly shaped glass fiber, it is necessary to rapidly solidify only a portion of the molten glass G to prevent the fiber's cross section from becoming rounded, while the remaining portion needs to be gradually solidified. For example, if the molten glass G on both long-diameter sides is rapidly solidified, the flattening will be increased, but the glass fiber will be more susceptible to cutting.

[0068] It should be noted that if Figure 6 As shown, if the cutout 54 b of the nozzle 5 that is constituted by only the nozzle row L1 and is not adjacent to the cooling pipe 6 does not face the cooling member 6 , the molten glass G cannot be sufficiently cooled.

[0069] In this embodiment, the intervals D1 and D2 are narrower than the width W at the front ends of the cutouts 54a and 54b. Therefore, it is possible to suppress the molten glass G from being excessively cooled.

[0070] The intervals D1 and D2 between the nozzles 5 are preferably 1 to 10 mm, more preferably 1 to 5 mm. This allows for a greater number of nozzles 5 to be arranged on the substrate 41. Furthermore, the width W at the tip of the cutout 54 is preferably 2 to 20 mm. The ratio of the width W at the tip of the cutout 54 to the intervals D1 and D2 (W / D(D1, D2)) can be, for example, 0.5 to 5, but is preferably 1.1 to 2.5.

[0071] Furthermore, the number of nozzles 5 included in one nozzle row L1 or L2 is preferably 10 to 500.

[0072] According to this embodiment in which the modified cross-section glass fiber is produced as described above, the following effects can be obtained.

[0073] In this embodiment, since the first nozzle row L1 and the second nozzle row L2 are arranged between the cooling area S (cooling pipe 6), more nozzles 5 can be arranged compared to conventional methods. This improves the productivity of special-shaped cross-section glass fibers. Furthermore, since more nozzles 5 are arranged, the number of glass fibers Gm produced at a time increases, resulting in the production of strands Gs with a larger count. Furthermore, in the nozzles 5 included in the first nozzle row L, one cutout 54a directly faces the cooling pipe 6, while the other cutout 54b faces the cooling pipe 6 via the gap between the nozzles 5 in the second nozzle row L2. This prevents excessive cooling of the molten glass G. Consequently, the viscosity of the molten glass G during forming can be appropriately adjusted, allowing for the stable formation of special-shaped cross-section glass fibers.

[0074] Furthermore, regarding the nozzles 5 included in the second nozzle row L, one cutout 54a directly faces the cooling pipe 6, and the other cutout 54b faces the cooling pipe 6 via the gap region between the nozzles 5 of the first nozzle row L1, thereby preventing the molten glass G from being excessively cooled.

[0075] As mentioned above, the method for producing a modified cross-section glass fiber according to the embodiment of the present invention has been described, but the present invention is not limited thereto, and various modifications can be made without departing from the scope of the present invention.

[0076] In the above embodiment, the intervals D1 and D2 between the nozzles 5 are equal, but the intervals D1 and D2 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.

Claims

1. A bushing, characterized in that: have: a substrate having a plurality of cooling regions extending in a predetermined direction and capable of being provided with a cooling member configured to cool the molten glass; as well as A plurality of nozzles are provided on the substrate, and each of the nozzles comprises, at a front end portion for the molten glass to flow out, a flat nozzle hole, a pair of first walls opposing each other in a short diameter direction of the nozzle hole and having a concave cutout, and a pair of second walls opposing each other in a long diameter direction of the nozzle hole. The bushing is provided with a plurality of nozzles so that the first wall portion faces the cooling area. Disposed between adjacent cooling zones are: a first nozzle array in which a plurality of the nozzles are arranged at predetermined intervals along an extending direction of the cooling region; as well as a second nozzle array, the second nozzle array being spaced apart from the first nozzle array and including a plurality of the nozzles arranged at predetermined intervals along an extending direction of the cooling region; The nozzles of the first nozzle array are arranged so that the cutouts provided on the pair of first wall portions of the nozzles can be opposed to the cooling area. In the plurality of nozzles included in the first nozzle array, one of the cutouts directly faces the cooling member, and another of the cutouts faces the cooling member via gaps between the nozzles in the second nozzle array.

2. The bushing according to claim 1, characterized in that The nozzles of the second nozzle array are arranged so that the cutouts provided in the pair of first wall portions of the nozzles can each face the cooling region.

3. The bushing according to claim 1 or 2, characterized in that: The intervals between the plurality of nozzles in the first nozzle row and the intervals between the plurality of nozzles in the second nozzle row are narrower than the width of the front end of the notch of the nozzle in the nozzle row.

4. A method for manufacturing special-shaped cross-section glass fiber, characterized in that: Using the bushing according to any one of claims 1 to 3, special-shaped cross-section glass fibers are produced.

5. The method for producing special-shaped cross-section glass fiber according to claim 4, characterized in that: The molten glass is E glass.

6. The method for producing special-shaped cross-section glass fiber according to claim 4 or 5, characterized in that: At the forming temperature, the molten glass has a 2.0 ~10 3.5 Viscosity in dPa·s.

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