JPH0360928B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a hollow fiber spinneret and a method for manufacturing the same.

Conventionally, in order to spin hollow fibers, as shown in FIGS. 1 and 2, an inflow hole 3 for the core liquid or core gas is provided in the center of the spinning solution introduction hole 2 of the spinneret body 1, and the spinning solution inflows in the circumferential direction. A liquid distribution plate 5 provided with holes 4 is fitted, and a core liquid or core gas discharge pipe 6 bored at the lower center of the liquid distribution plate 5 below is connected to the spinning liquid introduction hole 2. A hollow fiber spinneret 8 inserted into a narrow spinning solution discharge hole 7 is used.

That is, the spinning solution is introduced into the lower part of the spinning solution inlet hole 2 of the spinneret body 1 through the spinning solution inlet hole 4 in the circumferential direction of the liquid distribution plate 5, and the hollow fiber is discharged and spun from the spinning solution discharge hole 7, while the core The liquid or core gas flows into the liquid distribution plate 5 through the core liquid or core gas inflow hole 3 in the center of the liquid distribution plate 5.
The core liquid or core gas is extruded into the core liquid or core gas discharge pipe 6 at the lower center of the spinning solution discharge hole 7, and the core liquid or core gas is discharged into the inside of the hollow fiber to be spun to maintain the hollow shape of the hollow fiber. .

However, since the hollow fiber spinneret 8 has an extremely thin core liquid or core gas discharge pipe 6, it may bend if handled roughly. The liquid bends due to vibration, and if this continues repeatedly for a long time, it may break at the base.Furthermore, as mentioned above, when the core liquid or core gas discharge pipe 6 bends, the hollow fiber to be spun may be misaligned, that is, the hollow fiber may be bent. The centers of the inner circumferential circle and outer circumferential circle of the hollow fibers were offset, and the wall thickness varied in the circumferential direction, resulting in uneven thickness of the hollow fibers.

In order to eliminate such drawbacks, the present applicant previously provided a flange 9 on the inner peripheral wall of the spinning solution discharge hole 7, as shown in FIGS. 3 and 4, and inserted and held the discharge pipe 6 for the core liquid or core gas therethrough. At the same time, a hollow fiber spinneret 8' was developed in which a spinning solution flow hole 10 is provided in the circumferential direction of the flange 9. (Japanese Unexamined Patent Publication No. 57-183412) However, in this hollow fiber spinneret 8', since the cross-sectional area of the spinning solution flow hole 10 is small, the hollow fiber W to be spun becomes distorted as shown in FIG. be. Furthermore, since the spinning solution flow hole 10 is located away from the outer peripheral surface of the core liquid or core gas discharge pipe 6, the inner diameter of the obtained hollow fiber W changes over the entire length, that is, the wall thickness changes.

The present invention was made to solve this problem, and it is possible to spin hollow fibers that have a normal shape, have uniform thickness, and have a uniform wall thickness not only in the circumferential direction but also over the entire length. The purpose of the present invention is to provide a hollow fiber spinneret and a method for manufacturing the same.

An embodiment of the hollow fiber spinneret of the present invention is shown in the sixth and seventh embodiments.
This will be explained using figures. The same reference numerals as in FIGS. 1 and 2 indicate the same parts, and the explanation thereof will be omitted. Three arms 11 are provided protruding toward the center at equal angular intervals on the inner circumferential wall of the spinning solution discharge hole 7 of the spinneret body 1, and the core liquid or core gas is fed between the arcuate edges 11a at the tips of the arms 11. A discharge pipe 6 is inserted and held concentrically with the spinning solution discharge hole 7, and three fan-shaped spinning solution flow holes 12 are formed between the outer periphery of the discharge pipe 6 and the three arms 11.

In the above embodiment, three arms 11 are provided at equal angular intervals, and three fan-shaped spinning solution flow holes 12 are formed, but the invention is not limited to this. An arm 11 and a spinning solution flow hole 12 may be provided as shown in each case. In short, a plurality of arms 11 are provided at equiangular gaps, and a discharge pipe 6 for the core liquid or core gas is inserted and held concentrically with the spinning solution discharge hole 7 between the arcuate edges 11a at the tips of the arms 11. It is sufficient if a plurality of spinning solution flow holes 12 are formed between the outer periphery and each arm 11.

The manufacturing method of the present invention for manufacturing the hollow fiber spinneret 8'' having such a structure will be explained by taking as an example the case of manufacturing the hollow fiber spinneret shown in FIGS. 6 and 7. After drilling the spinning solution introduction hole 2 in the main body 1, a hole 13 having the same diameter as the core liquid or core gas discharge pipe 6 is bored through the bottom of the spinning solution introduction hole 2 by electric discharge machining. As shown in FIG. 9b, grooves 14 are cut on three sides at equal angular intervals by electric discharge machining in the outer circumferential direction of the center to form arms 11 between the grooves 14, and then the arms 11 are spun concentrically around the tips of the holes 13. The liquid discharge hole 7 is cut and then the core liquid or core gas discharge pipe 6 is inserted into the hole 13 as shown in FIGS. 6 and 7 and held at the arcuate edge 11a at the tip of the arm 11. The groove 14 serves as the spinning solution flow hole 12.

When the hollow fiber spinneret 8'' of the present invention made in this way is used to spin hollow fibers,
The spinning solution is introduced into the lower part of the spinning solution introduction hole 2 of the spinneret body 1 through the spinning solution inflow hole 4 in the circumferential direction of the liquid distribution plate 5, and is introduced to the outside of the spinning solution discharge hole 7 through the spinning solution distribution hole 12. Hollow fibers are extruded and joined together in the circumferential direction to form a hollow shape, and a hollow fiber is spun from the lower end thereof.
On the other hand, the core liquid or core gas is pushed out into the discharge pipe 6 through the inflow hole 3 at the center of the liquid distribution plate 5, and is discharged from the lower end of the spinning solution discharge hole 7 into the hollow fiber to be spun. Shape is retained.

In spinning such hollow fibers, the hollow fiber spinneret 8'' of the present invention has a plurality of pipes for discharging the core liquid or core gas that protrude toward the center from the inner circumferential wall of the spinning solution discharge hole 7. Since it is inserted and held between the tips of the arms 11, the core liquid or core gas discharge pipe 6 will not bend due to the vibration of the spinning solution, and will not break even after long-term use. Since there is no bending, the hollow fibers to be spun will not be misaligned, so that a uniform wall thickness can be obtained in the circumferential direction.In particular, the hollow fiber spinneret 8'' of the present invention has the advantage that the spinning solution flow holes 12 are Since the cross-sectional area is large, the hollow fibers to be spun have a normal shape and no uneven thickness. Moreover, since the spinning solution flow hole 12 is located on the outer periphery of the core liquid or core gas discharge pipe 6, the inner diameter of the obtained hollow fiber is uniform over the entire length, and there is no change in wall thickness.

Further, according to the hollow fiber spinneret and the manufacturing method thereof of the present invention, there is an advantage that a hollow fiber spinneret that exhibits the above-mentioned effects can be easily and precisely manufactured.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a conventional hollow fiber spinneret, Fig. 2 is a plan view thereof, Fig. 3 is a longitudinal cross-sectional view of another conventional hollow fiber spinneret, and Fig. 4 is a cross-sectional view of the same along line A-A. 5 is an enlarged view showing the cross-sectional shape of the defective hollow fiber spun by the hollow fiber spinneret in FIGS. 3 and 4;
Fig. 6 is a longitudinal cross-sectional view of the hollow fiber spinneret of the present invention, Fig. 7 is a cross-sectional view taken along line B-B, and Fig. 8 a, b, c.
9 is a cross-sectional view similar to FIG. 7 of another hollow fiber spinneret of the present invention, and FIGS. 9a and 9b are diagrams showing some steps of the method for manufacturing the hollow fiber spinneret of the present invention. 1... Spinneret body, 2... Spinning solution introduction hole, 3
...Inflow hole for core liquid or core gas, 4...Spinning liquid inflow hole, 5...Liquid distribution plate, 6...Discharge pipe for core liquid or core gas, 7...Spinning liquid discharge hole, 8''... Hollow fiber spinneret of the present invention, 11... arm, 11a...
...Arc-shaped edge at the tip of the arm, 12...Spinning solution flow hole, 13...Hole, 14...Groove.

Claims (1)

[Scope of Claims] 1. In a hollow fiber spinneret, a plurality of arms are protruded from the inner circumferential wall of the spinning solution discharge hole at equal angular intervals, and a discharge pipe for the core liquid or core gas is inserted between the tips of the arms. What is claimed is: 1. A hollow fiber spinneret, characterized in that a plurality of spinning solution flow holes are formed between an outer periphery of a discharge pipe of the hollow fiber spinneret and a plurality of arms. 2. After drilling a spinning solution introduction hole in the spinneret body, a hole with the same diameter as the core liquid or core gas discharge pipe is drilled at the bottom of the spinning solution introduction hole, and then the outer circumference is drilled around this hole. A plurality of grooves are cut at equal angular intervals in the direction to form an arm between the grooves, and then a core liquid or core gas discharge pipe is inserted into the hole and held at the tip of the arm. A method for manufacturing a hollow fiber spinneret, characterized in that the grooves serve as spinning solution flow holes.