JPH0781208B2 - Method and apparatus for producing inorganic continuous fiber - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing inorganic continuous fibers, and more particularly to a method and an apparatus for producing inorganic continuous fibers such as ceramic continuous fibers.

[0002]

2. Description of the Related Art In recent years, inorganic continuous fibers such as ceramic continuous fibers have been attracting attention as new materials. For such inorganic continuous fibers, a method of producing a continuous fiber precursor by firing is generally adopted. By the way, as one of the methods for producing a precursor of an inorganic continuous fiber, a spinning stock solution in which an inorganic compound is suspended and / or dissolved in a liquid such as water is discharged from a plurality of discharge holes formed in a spinneret. Then, there is a dry spinning method in which the yarn is discharged, and subsequently the discharged yarn is brought into countercurrent contact with the heating fluid to remove the solvent while the solvent is removed. In this dry spinning method, the spinning solution for inorganic continuous fibers is usually
The spinning speed of the inorganic continuous fiber is significantly lower than that of the synthetic fiber because the spinnability is inferior to that of the spinning dope for the synthetic continuous fiber. Therefore, as one means for improving the productivity of the inorganic continuous fibers, the ejection holes formed in the spinneret can be made porous.

In the porosity of the spinneret, the discharge yarns discharged from the discharge hole group formed near the center of the spinneret are discharged from the discharge hole group formed near the peripheral edge of the spinneret. As compared with the discharged yarn to be discharged, the contact with the heating fluid is likely to be insufficient, so that there is a problem that the solvent removal is likely to be insufficient. The following methods can be considered to solve this problem. Method of forcibly blowing heated fluid near the center of the spinneret The density of the discharge holes that are drilled near the center of the spinneret is
Method of making coarser than a group of discharge holes formed near the periphery of the spinneret

[0004]

According to the above method, the degree of contact between the heated yarn and the discharge yarn discharged from the discharge hole group near the center of the spinneret is improved as compared with the conventional method. However, the above-mentioned method has a drawback that the yarn sway of the discharged yarn becomes larger than that of the conventional one, and the fineness of the obtained inorganic continuous fiber tends to be nonuniform. In addition, although the method of (1) eliminates the drawback of yarn sway of the discharge yarn, in order to sufficiently remove the solvent from the discharge yarn and reduce the spinning breakage, the discharge hole that can be formed in the spinneret. Limited in number. In particular, when water having a large latent heat of vaporization is used as a solvent, such as a spinning dope for continuous ceramic fibers, it is necessary to make sufficient contact with a heating fluid in order to desolvate the discharged yarn. . For this reason, when spinning the precursor of the ceramic continuous fiber by the method, it is discharged from the spinneret as compared with the case of spinning the precursor of the inorganic continuous fiber using a spinning stock solution having a latent heat of vaporization smaller than that of water. There is no choice but to reduce the number of discharged single fibers (discharge filaments) or increase the diameter of the spinning tube (enlarge the spinning tube). For these reasons, at present, the number of discharge holes formed in a spinneret for producing a precursor for inorganic continuous fibers is at most 500.
It is a hall.

Therefore, an object of the present invention is to spin a stock solution using a solvent having a large latent heat of vaporization, such as water, to dry-spin a spinneret without increasing the size of a spinning cylinder. An object of the present invention is to provide a method for manufacturing an inorganic continuous fiber and a manufacturing apparatus for the same, which can make the die porous.

[0006]

Means for Solving the Problems As a result of various studies to achieve the above-mentioned object, the present inventors provided a spinning stock solution from the spinneret by providing a gap in the spinneret through which a part of heating fluid can pass. It was found that the entire discharged yarn obtained by discharging and the heated fluid can be evenly contacted,
The present invention has been reached. That is, according to the present invention, a spinning stock solution in which an inorganic compound such as an aluminum compound is suspended and / or dissolved in a solvent such as water is discharged from a plurality of discharge holes formed in a spinneret located above a spinning cylinder. When the inorganic continuous fiber is produced by a dry spinning method in which the yarn is discharged to form a discharged yarn, and subsequently the discharged yarn is brought into countercurrent contact with a heating fluid to remove the solvent while removing the solvent, the plurality of discharge holes are formed. The one discharge hole group and the other discharge hole group are separated by a gap so that the end faces of the spinneret on the spinning cylinder side in which the discharge holes forming each of the discharge hole groups are formed are in the same horizontal plane. Inorganic continuous fiber, characterized in that at least a part of the heating fluid countercurrently contacting the discharge yarn discharged from each discharge hole of the discharge hole group is discharged from the gap to the outside of the spinning cylinder. In the manufacturing method.

In the present invention, a spinning stock solution in which an inorganic compound such as an aluminum compound is suspended and / or dissolved in a solvent such as water is provided in a plurality of spinnerets located above a spinning cylinder. In an apparatus for producing an inorganic continuous fiber based on a dry-spinning method, which discharges from a discharge hole to form a discharge yarn, and subsequently, the discharge yarn is brought into countercurrent contact with a heating fluid to pull it out, a group consisting of the plurality of discharge holes The discharge hole group and the other discharge hole group are arranged such that the end faces of the spinneret side of the spinneret in which the discharge holes forming the discharge hole group are formed are in the same horizontal plane. An interval is provided between the discharge hole group and the other discharge hole group so that at least a part of the heating fluid in countercurrent contact with the discharge yarn discharged from each discharge hole can be discharged to the outside of the spinning tube. It is also an apparatus for producing inorganic continuous fibers. Such a gap may be formed by using a split spinneret provided in each of the spinnerets in which a discharge hole group consisting of a plurality of discharge holes and the other discharge hole group are divided. The discharge hole group and the other discharge hole group may be formed in the same spinneret.

[0008]

In the present invention, since a gap is formed between one discharge hole group and the other discharge hole group, the heating fluid passes through and is discharged to the outside of the spinning cylinder. And the discharge yarns discharged from each discharge hole group are sufficiently contacted, and the solvent can be sufficiently removed from the discharge yarns. In addition, when attempting to make the spinneret porous, the gap formed between the one discharge hole group and the other discharge hole group
Since the size of each discharge hole group can be set to such a number that the discharge yarn and the heating fluid can be sufficiently contacted with each other, the discharge hole density between the central portion and the peripheral portion of the spinneret is adjusted. Can be eliminated. Therefore, according to the present invention, the spinneret can be made porous without increasing the size of the spinning cylinder or the like.

[0009]

In the present invention, as shown in FIG. 1, it is essential that a spinneret is disposed above the spinning cylinder with a gap. FIG. 1 is a schematic diagram showing an embodiment of the present invention. In FIG. 1, a plurality of spinning packs 1, 1, ... Are arranged above a spinning cylinder 2. As will be described later, a spinneret having a plurality of ejection holes is provided on each lower surface of the spinning packs 1, 1 ,. From these discharge holes, the spinning dope is simultaneously discharged into the spinning cylinder 2 to obtain the discharged yarns 7, 7, .... Each of the discharge filaments constituting the obtained discharge yarn travels in the spinning tube 2 in countercurrent contact with a heating fluid such as a heating air stream while being desolvated, and is converged and combined by a converging pin 9. After that, it is wound up by the winding device 11. At this time, the winding speed is 100
It is preferably m / min or less because the discharged yarn can be sufficiently dried. The lower limit of the winding speed is
It is arbitrarily determined in relation to productivity. In addition, the heating fluid such as the heating air stream is heated by the heating unit 13 provided in the lower portion of the spinning tube 2.
After being heated by, the fluid is supplied into the spinning tube 2 through the heating fluid supply holes 15, 15 ... Opened in the lower wall surface of the spinning tube 2.

As shown in FIG. 2, the spinning stock solution supplied to each of the plurality of spinning packs 1, 1, ... Is fed to each spinning pack 1 from the stock solution hopper via the metering pump 3 and the filter 5. Liquid is sent. In the supply pipe 18 for sending the spinning dope and the branch pipe 19 for supplying the spinning dope to each spinning pack 1, the pipe length from the raw material hopper to each spinning pack is made as long as possible, and / or By branching the branch pipe 19 from the reservoir (chamber) provided near the tip of the supply pipe 18 to each spinning pack 1, the supply pressure of the spinning dope flowing into each spinning pack 1 is made as uniform as possible. Pressure can be applied, and the resulting inorganic continuous fibers can be made even more uniform.

In the spinning device shown in FIG. 1, each spinning pack 1 is equipped with each of the divided spinnerets.
It is important that the spinnerets of the spin packs 1 ... Are arranged with a gap so that the end faces of the spinnerets on the spinning cylinder side are in the same horizontal plane. Therefore, the discharge yarns 7, 7, ... Are divided into a plurality of pieces and discharged, and a part of the heating fluid rising in the heating cylinder 2 passes through the gap and is discharged to the outside of the spinning cylinder 2. According to the present invention, the discharge yarns can be divided into as small groups as possible to be discharged, and the heating fluid can be caused to flow so as to wrap each discharge yarn. Therefore, each of the discharge filaments forming the discharge yarn and the heating fluid can be brought into sufficient contact with each other. Moreover, in the present invention, since a plurality of small spin packs are provided, the degree of contact between the discharge filament and the heated fluid can be ignored in the vicinity of the central portion and the peripheral portion of the spinneret, and the spinneret can be drilled. The total number of discharge holes can be easily increased without changing the discharge hole density or the like. Therefore, the total number of discharge holes is 1000
Even if the number of holes is not less than the above value, it is possible to sufficiently remove the solvent from the discharged yarn while maintaining good spinning performance.
Further, as shown in FIG. 1, since the spinning packs 1, 1, ... Are divided, even if the discharging yarn discharged from one spinning pack is broken, another fragment of the discharging yarn is used. Does not break the yarn discharged from the spinning pack. Also,
The operation for re-discharging the spinning dope from the broken spin pack 1 can also be performed without stopping the discharge of another spinning pack.

The spinning pack 1 used in FIG.
Is shown in FIG. FIG. 3 is a vertical cross-sectional view of the spinning pack 1. The lower surface of the rectangular house 21 of the spinning pack 1 is provided with a spinneret 23 having a rectangular planar shape obtained by processing a stainless steel plate or the like. The spinneret 23 is provided with a plurality of discharge holes 25 in a grid pattern. As shown in FIG. 4, the discharge hole 25 is formed in the lower portion of the stock solution introducing hole 33 at the tip of the protrusion 35 discharged from the lower surface of the spinneret 23. With this discharge hole 25, wetting of the spinning dope at the outlet of the discharge hole can be reduced, separation of the spinning dope from the discharge port is improved, and the spinning dope is stabilized in combination with the rectifying effect of the spinning dope in the protrusion 35. Spinning can be performed.
Further, on the side surface of the rectangular house 21, a stock solution supply hole 27 is formed near the upper surface of the spinneret 23 to connect a stock solution supply pipe 19 for supplying the stock solution for spinning into the rectangular house 21. In the spinning pack 1 shown in FIG. 3, the rectangular house 2
When the spinning dope is supplied so that the air layer 31 is formed on the upper surface of the spinning dope layer 29 in the first spinning dope layer 1, the spinning dope layer 29 having a uniform thickness is formed on the upper surface of the spinneret 23, and the spinning holes 25 are spun from the respective discharge holes 25. The stock solution can be evenly discharged.

1 and 2 described above, the spinning packs 1, 1 ...
In the example shown in FIG. 5, the lower surface of the spinneret is arranged so as to be in the same horizontal plane through a gap.
As shown in, a plurality of discharge hole groups may be formed in the same spinneret, and a gap through which a part of the heating fluid passes and is discharged to the outside of the spinning cylinder 2 may be provided. In FIG. 5a, a discharge hole 25 is concentrically formed in a circular spinneret 23, and a plurality of circular gaps 50 through which a part of heating fluid passes are provided at the center of the spinneret 23 and its periphery. It is a thing. Further, in FIG. 5b, the discharge holes 25 are formed in a lattice shape in the rectangular spinneret 23, and a plurality of slit-shaped gaps 50 through which a part of the heating fluid passes are provided in parallel with the spinneret 23. Is.

The present invention will be described in more detail by way of examples.

Examples (1) Preparation of spinning dope 19.4 kg of an aqueous solution of basic aluminum chloride containing 13.9% by weight of Al ions and having a basicity of 80%, SiO ₂
In a mixture of 4.5 kg of colloidal silica containing 20% by weight, 1.5 kg of polyvinyl alcohol having an average polymerization degree of 1700 and a saponification degree of 88% is dissolved as a spinning aid,
Concentration under reduced pressure gave a spinning dope of 840 poise (25 ° C). (2) Spinning device A spinneret in which 167 discharge holes 25 shown in FIG. 4 are formed (a discharge hole row having a discharge hole interval of 5 mm is arranged in three rows in a lattice pattern).
Each of the six sets of the spinning packs 1 equipped with the spinnerets 1 is arranged on the upper part of the spinning cylinder 2 with a predetermined gap so that the end faces of the spinnerets mounted on the respective spinning packs 1 are on the same horizontal plane. Was installed (total number of discharge holes: 1002). Spin pack 1, 1 ・
As shown in FIG. 2, a spinning stock solution is supplied from each stock solution hopper through the metering pump 3 and the filter 5 to each of the. A jacket for cooling the spinning pack 1 is provided above each spinning pack 1, and cooling water having a water temperature of 15 ° C. was constantly passed.

The spinning stock solution previously adjusted in (1) was supplied to the stock solution hopper of the spinning apparatus, and the metering pump 3 was started to supply the spinning stock solution to each spinning pack 1, resulting in 6 sets of spinning packs 1, 1. The discharge of the spinning dope was started all at once from all the discharge holes 25 of the spinneret attached to each. Next, the discharged yarn was taken up by the winding device 11 at a take-up speed of 40 m / min while making countercurrent contact with the heated air flow inside the spinning tube 2. At this time, the temperature of the heated air stream supplied from the lower part of the spinning tube was set to 80 ° C., and the ambient temperature near the lower surface of the spinneret was 4 °
The amount of heated air was adjusted so that the temperature became 0 ° C. In this example, spinning was continuously performed for about 30 hours, but spinning could be completed without trouble such as spinning breakage. Then, the obtained spun yarn composed of 1002 filaments was fired at about 1200 ° C. to obtain an alumina-silica series ceramic long fiber bundle.

Fifty filaments were randomly sampled from the obtained ceramic long fiber bundle, cut into fiber lengths of 25 mm, and the fiber diameter, tensile strength, and tensile elastic modulus were measured. Fiber diameter 7.3 μm Tensile strength 183 kg / mm ² Tensile modulus 17 ton / mm ²

Comparative Example The same procedure as in Example was repeated except that a spinning pack equipped with a disk-shaped spinneret having a diameter of 28 cm was used in place of the split spinning pack used in Example. In the disk-shaped spinneret, as in the case of the spinneret of the example, 1000 discharge holes 25 shown in FIG. 4 were formed in a puddle shape with a hole gap of 7 mm. When spinning is started, discharge filaments are smoothly formed in the discharge holes near the periphery of the spinneret,
In the ejection hole near the center, the meniscus formed in the ejection portion became abnormally thick, and frequent yarn breakage occurred. Moreover, even if the temperature of the heated air stream is gradually raised from 80 ° C. to raise the atmospheric temperature near the lower surface of the spinneret to 40 ° C. or higher, the spinning condition is not improved and the discharge holes near the periphery of the spinneret are not improved. Since the blockage phenomenon had occurred in the above, spinning was abandoned.

[0018]

According to the present invention, even in the case of a precursor of inorganic continuous fiber having a slow spinning speed, the productivity can be easily improved by making the spinneret porous, and the cost of the final product can be significantly reduced. be able to.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a route for supplying a spinning dope to each of the spinning packs shown in FIG.

FIG. 3 shows a longitudinal sectional view of the spinning pack used in FIGS. 1 and 2.

FIG. 4 shows a sectional view of a discharge hole formed in a spinneret.

FIG. 5 is a plan view showing another embodiment of the spinneret.

[Explanation of symbols]

 1 Spinning pack 2 Spinning cylinder 7 Discharge yarn 23 Spinneret 25 Discharge hole

Claims (6)

[Claims] 1. A spinning stock solution in which an inorganic compound such as an aluminum compound is suspended and / or dissolved in a solvent such as water is discharged from a plurality of discharge holes formed in a spinneret located above a spinning cylinder. When a continuous fiber is produced by a dry spinning method in which the discharge yarn is continuously brought into contact with a heating fluid countercurrently to remove the solvent while being taken out, a group of a plurality of discharge holes is formed. The discharge hole group and the other discharge hole group are separated by a gap so that the end faces of the spinneret on the spinning cylinder side in which the discharge holes forming each of the discharge hole groups are formed are in the same horizontal plane. Disposed at least a part of the heating fluid in countercurrent contact with the discharge yarn discharged from each discharge hole of the discharge hole group is discharged from the gap to the outside of the spinning cylinder. Production method. 2. The method for producing an inorganic continuous fiber according to claim 1, wherein one discharge hole group consisting of a plurality of discharge holes and the other discharge hole group are provided in each of the divided spinnerets. 3. The method for producing an inorganic continuous fiber according to claim 1, wherein one discharge hole group consisting of a plurality of discharge holes and the other discharge hole group are provided in the same spinneret. 4. A spinning stock solution in which an inorganic compound such as an aluminum compound is suspended and / or dissolved in a solvent such as water is discharged from a plurality of discharge holes formed in a spinneret located above a spinning cylinder. In a device for producing an inorganic continuous fiber based on a dry spinning method in which a discharge yarn is formed, and the discharge yarn is then brought into countercurrent contact with a heating fluid and drawn, a discharge hole group consisting of a plurality of discharge holes is formed. And the other discharge hole group are arranged so that the spinning cylinder side end surface of the spinneret in which the discharge holes forming the discharge hole group are formed are in the same horizontal plane, and the one discharge hole group An interval is provided between the other discharge hole group and at least a part of the heating fluid countercurrently contacting the discharge yarn discharged from each discharge hole can be discharged to the outside of the spinning tube. Inorganic continuous fiber manufacturing equipment. 5. The apparatus for producing an inorganic continuous fiber according to claim 4, wherein a group of discharge holes composed of a plurality of discharge holes and another discharge hole group are provided in each of the divided spinnerets. 6. The apparatus for producing an inorganic continuous fiber according to claim 4, wherein one discharge hole group consisting of a plurality of discharge holes and the other discharge hole group are provided in the same spinneret.