阅读说明：本技术 玻璃纤维制造用拉丝坩埚 (Glass fiber manufacturing is with wire drawing crucible ) 是由 多田智之 大泽年宽 长尾直也 中冈笃司 于 2019-09-06 设计创作，主要内容包括：本发明涉及具备底板和排出熔融玻璃的两个以上喷嘴且通过在所述底板上接合将所述两个以上喷嘴整列配置而形成的喷嘴组而成的玻璃纤维制造用拉丝坩埚。在本发明中,所述喷嘴组的至少构成最外层的列的喷嘴上形成有由陶瓷构成的涂层。涂层没有覆盖整个喷嘴,而是成为在喷嘴前端附近没有涂层的状态。本发明是能够抑制不规则现象的发生、长期稳定地形成均匀的玻璃液流的玻璃纤维制造用漏板。(The present invention relates to a bushing for manufacturing glass fibers, which includes a bottom plate and two or more nozzles for discharging molten glass, and which is formed by joining a nozzle group formed by arranging the two or more nozzles in a row to the bottom plate. In the present invention, a coating layer made of ceramic is formed on the nozzles of at least the outermost row of the nozzle group. The coating does not cover the entire nozzle, but is in a state where there is no coating in the vicinity of the nozzle tip. The invention provides a bushing for manufacturing glass fiber, which can inhibit the generation of irregularity and stably form uniform glass liquid flow for a long time.)

1. A glass fiber-producing bushing comprising a bottom plate and two or more nozzles for discharging molten glass, wherein the two or more nozzles are arranged in a row and joined to the bottom plate,

a coating layer made of ceramics is formed on the nozzles of the nozzle group which at least form the outermost row,

the nozzle having the coating layer formed thereon forms a coating layer having a length of 50% or more and 90% or less with respect to the entire nozzle length when no coating layer is formed on the end surface on the glass discharge side and the nozzle tip portion.

2. A glass fiber-producing bushing comprising a bottom plate and two or more nozzles for discharging molten glass, wherein the two or more nozzles are arranged in a row and joined to the bottom plate,

a coating layer made of ceramics is formed on the nozzles of the nozzle group which at least form the outermost row,

the nozzle on which the coating layer is formed does not have a coating layer formed on the end surface on the glass discharge side and the region 0.1mm to 2mm from the edge portion.

3. The bushing for producing glass fibers according to claim 1 or claim 2, wherein a coating layer made of ceramic is further formed on at least a part of the bottom plate.

4. The bushing for producing glass fibers according to any one of claims 1 to 3, wherein the thickness of the coating layer is 50 μm or more and 500 μm or less.

5. A method for producing glass fibers, wherein the bushing for producing glass fibers according to any one of claims 1 to 4 is used.

6. A method for producing a glass fiber-producing bushing according to any one of claims 1 to 4, comprising:

a cap covering the nozzle end face and the nozzle tip portion is provided on the nozzle cap on which the coating is to be formed, and then the coating is performed.

7. A method for producing a glass fiber-producing bushing according to any one of claims 1 to 4, comprising:

a nozzle for forming a coating layer is coated by pressing a filler into the nozzle from an inlet of molten glass, projecting the filler from a discharge port of the nozzle, deforming the projecting filler so as to cover an end face of the nozzle and a tip portion of the nozzle.

8. The method of manufacturing a bushing for manufacturing glass fibers according to claim 6 or claim 7, wherein the coating is performed after shielding a part or all of the bottom plate from the nozzles other than the outermost nozzles of the nozzle group.

Technical Field

The present invention relates to a bushing (bushing) for producing glass fibers from molten glass. More particularly, the present invention relates to a bushing for manufacturing glass fibers, which can stably discharge a glass flow and perform drawing of glass fibers when the bushing is used for a long period of time.

Background

Glass fibers are produced by supplying a glass material, which is obtained by refining and homogenizing a molten glass obtained by heating a glass raw material (cullet) at a high temperature, to a bushing. The bushing for producing glass fibers is a box-shaped vessel having a bushing (bursting plate) for discharging glass fibers on the bottom surface. In addition, in the bushing, two or more nozzles are mounted in a line on the bottom surface of the bottom plate, and the glass material is discharged from the nozzles in a fibrous form. The glass fiber discharged from the nozzle is wound while being cooled. An example of a process for producing glass fibers using such a bushing is a method described in patent document 1.

The bushing for glass production is generally made of a noble metal material such as platinum or a platinum alloy. The noble metal material is excellent in chemical stability and high-temperature strength, and particularly excellent in high-temperature creep characteristics, and is suitable as a constituent material of a structure which is subjected to a stress load at high temperature such as a glass production apparatus.

Documents of the prior art

Patent document

Patent document 1: japanese Kohyo publication No. 2001-513478

Disclosure of Invention

Problems to be solved by the invention

A bushing made of a noble metal material such as platinum can perform stable drawing of glass fibers even in a high-temperature environment in which molten glass flows. However, according to the field investigation of the present inventors, it was grasped that: there are cases where uniform glass fibers cannot be obtained during long-term device use. Such inhomogeneity of the glass fiber is considered to be caused by irregularities such as disturbance of glass flow and generation of foreign matter in drawing the glass fiber. The occurrence of these irregularities hinders the stable production of glass fibers even if the irregularities are localized to the glass flow discharged from all the nozzles of the bushing.

Accordingly, an object of the present invention is to provide a bushing for manufacturing glass fibers, which can suppress the occurrence of various irregularities and can stably form a uniform glass flow for a long period of time.

Means for solving the problems

In order to solve the above problems, the present inventors have studied the main cause of the irregularity phenomenon observed in the glass flow discharged from the nozzle. As a result, attention is paid to the conditions of the bushing in the vicinity of the nozzle, the phenomenon of volatilization loss of platinum on the nozzle surface, and the behavior of platinum volatilized.

The glass material supplied to the bushing is a high-temperature molten glass of 1500 ℃ or higher. Platinum and platinum alloys are high melting point metallic materials, but are volatile at high temperatures. Further, the discharge speed of the fibrous glass from the nozzle reaches several kilometers per minute, and a high-speed air flow is generated in a certain direction around the nozzle which discharges the high-temperature fluid at a high speed. Further, according to the observation results of the present inventors, the high-speed gas flow transports platinum volatilized from the nozzles to the vicinity of the base plate at a high speed. Thus, the nozzle is quickly worn and thinned. The platinum volatilized and transported to the vicinity of the substrate is cooled to become fine lumps of platinum, and the platinum is attached to the surface of the substrate (hereinafter, the fine lumps of platinum are referred to as "platinum lumps"). The platinum block is basically adhered to the surface of the base plate, but may be detached and mixed as foreign matter into the product.

Therefore, the present inventors conceived the present invention of forming a coating layer on the nozzle surface in order to suppress the volatilization loss of platinum of the nozzle of the bushing.

That is, the present invention is a bushing for manufacturing glass fibers, which is provided with a bottom plate and two or more nozzles for discharging molten glass, and which is formed by joining a nozzle group formed by arranging the two or more nozzles in a row to the bottom plate, wherein a coating layer made of ceramic is formed on at least the nozzles in the row constituting the outermost layer of the nozzle group, and the nozzles on which the coating layer is formed have a coating layer having a length of 50% or more and 90% or less with respect to the entire nozzle length when no coating layer is formed on the end face on the glass discharge side and the tip end portion of the nozzle.

The present invention is also a bushing for manufacturing glass fibers, comprising a bottom plate and two or more nozzles for discharging molten glass, wherein a nozzle group formed by arranging the two or more nozzles in a row is joined to the bottom plate, wherein a coating layer made of ceramic is formed on at least the nozzles in the row constituting the outermost layer of the nozzle group, and the nozzles on which the coating layer is formed are not coated on the end surface on the glass discharge side and the region 0.1mm to 2mm from the edge portion.

As described above, the bushing for manufacturing glass fibers according to the present invention has a coating layer formed on the nozzles in at least the outermost row of the nozzle group. The nozzle having the coating layer formed thereon is in a state where the coating layer is not formed on the end surface and the tip portion on the glass discharge side.

The bushing, the bottom plate, and the like for manufacturing glass fibers according to the present invention have the same structure as the conventional bushing. The characteristics of the bushing for manufacturing glass fibers according to the present invention will be described in detail below.

The bottom plate is a member for holding a glass material in a molten state, and is a plate-like member or a member having a box shape by bending. The bottom plate has a through hole at a connection position with the nozzle. The material of the base plate includes platinum or a platinum alloy, and preferably, in addition to platinum and a platinum-rhodium alloy (rhodium concentration: 5 to 20 mass%), a dispersion-strengthened platinum alloy or a dispersion-strengthened platinum-rhodium alloy is used for the purpose of improving the strength.

As the nozzle, a nozzle used in a bushing for producing glass fibers in the related art is basically applied. More than two nozzles are joined in an aligned arrangement on the bottom surface of the bottom plate. The shape of the nozzle is not particularly limited, and may be a straight tube or a tapered tube with a thin tip. Further, platinum or the platinum alloy is also used as a material of the nozzle.

In the present invention, at least the outermost nozzle row of the nozzle group is coated (see fig. 1). The reason why the outermost columns must be coated is that the outermost columns are particularly affected by the high-speed gas flow, and are worn and thinned by the combination of platinum volatilization and the gas flow. The outermost rows are rows at both ends of the nozzle groups arranged in the row in the longitudinal and transverse directions.

The coating of the nozzle does not necessarily have to cover the entire nozzle without gaps. That is, the end surface of the nozzle on the glass discharge side is not coated with a coating layer. In addition, a region having no coating is also set at the tip end portion of the nozzle side surface in addition to the nozzle end surface. Depending on the operating conditions of the glass manufacturing apparatus, the molten glass may rise from the nozzle end face to the side face of the nozzle tip. When the molten glass climbing up comes into contact with the coating layer, the coating layer may disappear. Therefore, the nozzle is set to have a coating region of an appropriate length to prevent the molten glass from contacting the coating.

When the area of the nozzle where the coating layer is formed is set at a ratio to the length of the entire nozzle length, the area is set so as to cover a range of 50% to 90% of the entire nozzle length. That is, a region of less than 50% and more than 10% with respect to the entire nozzle length is regarded as a non-coating region. The setting conditions take into account the complicated influences such as the rising of the molten glass and the consumption of the nozzle tip, which may occur depending on various operating conditions. The overall length of the nozzle means the length in the vertical direction from the nozzle tip to the base of the nozzle (the joint with the base plate).

In addition, it is sometimes convenient to set the region where the coating layer is formed with a specific size value depending on the operating conditions and the like. Specifically, the nozzle end face on the glass discharge side and the region 0.1mm to 2mm from the edge of the nozzle end face are set as the regions where no coating is formed, and the other regions are set as the coated regions. The distance from the edge portion of the nozzle means a distance measured from the edge of the nozzle along the side of the nozzle.

In the bushing for manufacturing glass fibers of the present invention, the nozzles of the nozzle group constituting at least the outermost row are coated in a region having one of the two conditions. It should be noted that any one of the above two conditions may be provided, but as a result, two conditions may be provided.

In addition, in the bushing for manufacturing glass fiber, the number of nozzles is not particularly limited, but generally 200 to 10000 nozzles are often provided. In this case, the nozzle groups arranged at a constant interval may be arranged in two or more island shapes. When a coating layer is set to the outermost nozzle row of the nozzle groups, the coating layer may be formed to the outermost nozzle row along the four sides of the bottom plate of each nozzle group.

In the present invention, the coating layer is formed at least on the outermost row of the nozzle group, but the coating layer may be formed on the entire nozzle group (see fig. 2). This is because the influence of platinum volatilization due to high-temperature heating may occur in the entire nozzle group, and it is sometimes preferable to protect the nozzle rows inside the nozzle group with a coating layer.

Further, the coating layer may be formed on the base plate in addition to the nozzle. There is also not a complete absence of the possibility of platinum volatilizing on the substrate. By forming the coating on the entire lower surface of the bushing, concerns about platinum volatilization can be eliminated.

In the case where a coating layer is formed on the base plate in addition to the coating layer formed on the nozzle, at least a part of the coating layer may be coated. For example, a pair of plate-shaped coatings having a width may be formed along any one of the long or short sides of the base plate, or a frame-shaped coating having a width may be formed along four sides of the base plate. Further, a coating layer may be formed on the entire surface of the base plate (see fig. 3).

The material of the coating is preferably at least one of alumina, zirconia, and yttria-stabilized zirconia. This is to consider suppression of platinum volatilization under high-temperature heating and protection against abrasion by high-speed gas flow at high temperature. In particular, a coating material containing yttria-stabilized zirconia is useful for preventing volatilization of molten glass used for forming the long glass fiber filler.

The thickness of the coating layer is preferably set to 50 μm or more and 500 μm or less. If the coating is too thin, the desired protective effect is not obtained, while if the coating is too thick, peeling may occur even if the nozzle or the plate is slightly deformed. The form of the coating layer is preferably a thermal spray coating. Sputtering is a suitable method for forming the ceramic film having the above-described preferred film thickness. The thermal spray coating is a relatively dense coating film and can effectively function as a protective layer.

Effects of the invention

As described above, the bushing for manufacturing glass fibers according to the present invention has a coating layer formed at least on the nozzle, compared to the conventional bushing. This is to suppress volatilization of platinum, which is a constituent material of the nozzle, and to avoid an influence of a high-speed airflow around the nozzle. According to the present invention, irregularities such as disturbance of glass flow and generation of foreign matter during drawing of glass fibers can be suppressed, and long-term use of the apparatus is possible.

The bushing for producing glass fibers of the present invention is particularly suitable for producing glass fibers of long fibers having a small number of filaments. This is because, according to the effect of the present invention, there is a concern that the number of fine glass fibers, such as broken filaments and fluctuations in the number of fine glass fibers, may be reduced.

Drawings

FIG. 1 is a view showing one embodiment (coating is performed only on the outermost nozzle row) of a bushing for manufacturing glass fibers according to the present invention.

FIG. 2 is a view showing one embodiment (coating of all nozzles) of a bushing for producing glass fibers according to the present invention.

FIG. 3 is a view showing one embodiment (coating of the base plate and all the nozzles) of the bushing for manufacturing glass fibers according to the present invention.

Fig. 4 is a view of a bushing for manufacturing glass fibers according to the present embodiment.

Fig. 5 is a diagram illustrating a method (silicon cap) for treating the nozzle tip when forming a coating layer in the present embodiment.

Fig. 6 is a diagram for explaining another method of processing the nozzle tip when forming the coating layer.

Detailed Description

Hereinafter, embodiments of the present invention will be described. Fig. 4 shows a bushing 100 for manufacturing glass fibers manufactured in the present embodiment. In fig. 4, the bushing for manufacturing glass fibers includes a base plate 10 and two or more nozzles 20 arranged in a row on the bottom surface thereof.

The base plate 10 is made of a platinum plate (bottom surface size: 444 mm. times.120 mm, thickness: 1.5 mm). The nozzles 20 are joined to the base plate 10 so that 4 nozzle groups are formed in an island shape. In each nozzle group, 20 × 20 pieces were joined at intervals of 6.4 mm. The total number of nozzles engaged on the base plate 10 is 1600. The nozzles 20 are each a tapered cylindrical body having an outer shape of 2.94mm (upper end outer diameter) × 2.35mm (lower end outer diameter). The overall length of the nozzle joined to the base plate was 4 mm. The base plate and the nozzle were made of platinum.

In the bushing 100 for manufacturing glass fibers according to the present embodiment, a coating of yttria-stabilized zirconia is formed on all of the nozzles 20 and the base plate 10. The coating layer was not formed on the end face of the nozzle and on the region within 0.8mm in the vertical direction from the nozzle tip, and the base metal was exposed in this region. That is, the coating layer was formed in a region having a length of 80% with respect to the entire nozzle length. The thickness of the coating layer is 300 μm or less.

In the manufacturing process of the bushing for manufacturing glass fibers according to the present embodiment, the nozzles 20 processed to the above-described dimensions by punching are joined to the base plate 10 in an aligned manner. In the joining of the nozzle 20, the nozzle 20 is inserted into the nozzle hole in advance at each nozzle mounting portion of the base plate 10, and then the base plate is preliminarily joined by heating in an electric furnace, and further the root portion of the joined portion is welded from the upper surface (molten glass inflow surface) of the base plate by a YAG laser. Thereby, a bushing before coating is manufactured.

Before the coating was formed, a cap made of silicon was attached to the tip end of each nozzle (fig. 5). Then, a coating layer is formed on the entire surface of the bushing by a thermal spraying method. After the coating layer is formed, the silicon cap is removed to produce the bushing for producing glass fibers of the present embodiment.

In the present embodiment, a silicon cap is provided at the tip of the nozzle in the method of locally forming the coating layer on the nozzle. In addition to this method, there is a method of: a filler containing resin such as clay or modified silicone is pushed in from the back surface (molten glass inflow surface) of the bottom plate, the filler is extruded from the discharge port of the nozzle and projected, the projected filler is crushed and deformed so as to cover the tip portion of the nozzle, and then coating is performed, thereby covering the portion other than the tip portion of the nozzle (fig. 6).

In the present embodiment, the coating layer is formed on the entire surface after the silicon cap is used for masking. As mentioned above, the coating may also be topical. At this time, the coating layer can be formed in a desired region by masking a part or the whole of the base plate and the nozzles other than the outermost nozzles of the nozzle group and then coating.

In addition, as an example of producing glass fibers using the bushing for producing glass fibers of the present embodiment, first, a terminal and a box-shaped side flange are joined to the bushing to form a bushing as a box-shaped container. The bushing was assembled into a glass manufacturing apparatus. The glass manufacturing apparatus includes a melting tank for preparing a glass raw material having a target composition, a clarifying tank for molten glass, and a stirring tank for stirring and homogenizing the clarified molten glass, and a bushing is provided downstream of the melting tank and the clarifying tank. The glass fiber discharged from the bushing is appropriately wound.

Here, glass fiber production was performed for 1 year by using the glass production apparatus including the bushing for glass fiber production according to the present embodiment. During this time, no visually apparent abnormality was observed on the bushing, and the fiber glass was also stably drawn. Then, after 1 year of operation of the apparatus, the apparatus was closed and the nozzle of the bushing was inspected. As a result, no platinum lumps were observed on the substrate. In addition, the first and second substrates are,with respect to the nozzle, although about 0.1mg/mm was observed²About 0.2mg/mm²The coating was slightly worn but no thinning of the platinum matrix of the nozzle was observed.

Industrial applicability

According to the bushing for manufacturing glass fibers of the present invention, the glass manufacturing apparatus can be stably used for a long period of time, and high-quality glass fibers can be efficiently manufactured.