JPH02441B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a spinneret.

In order to manufacture a spinneret, for example, a hollow fiber spinneret, conventionally, as shown in FIG. As shown in FIG. 1b, a C-shaped polymer discharge hole 3, that is, a partially interrupted annular polymer discharge hole 3, was bored through the bottom of the hole 2 to form a spinning hole 4.

The molten polymer discharged from the polymer discharge hole 3 of the hollow fiber spinneret 5 made in this way is
Immediately after spinning, both ends of the C-shaped cross section are welded together to form a circular hollow fiber 6 as shown in FIG.
Since the upper surfaces of the core bar 7 and its connection portion 8 inside the polymer discharge hole 3 are flat, and the width of the connection portion 8 is thin and weak, it is difficult to obtain a normal hollow fiber 6 as shown in FIG. 2 at the beginning of use. However, when used for a long period of time, the core bar 7 deforms and sags as shown in Figure 3 due to the high heat of the molten polymer and high spinning pressure, and the wall thickness varies in the circumferential direction as shown in Figure 4a. In other words, an abnormally misaligned hollow fiber 6' is obtained. As the core bar 7 continues to sag,
It falls off as shown by the chain line in FIG. 3, and as a result, an abnormal solid yarn 6'' as shown in FIG. 4b is obtained.

The present invention has been made in order to eliminate such drawbacks, and it is an object of the present invention to provide a method for manufacturing a spinneret in which the core bar inside the polymer discharge hole is never deformed or falls off.

Hereinafter, one embodiment of the method for manufacturing a spinneret according to the present invention will be described with reference to the drawings. As shown in FIG. An arc-shaped reinforcing rib 9 is provided protruding from the inner circumferential surface of the hollow part to the bottom surface, and then a C-shaped, that is, straight, arc-shaped reinforcing rib 9 is provided at the bottom of the polymer introduction hole 2, avoiding the reinforcing rib 9, as shown in FIG. 5b. A partially interrupted annular polymer discharge hole 3 is penetrated to form a spinning hole 4'.

The upper surface shape of the arcuate reinforcing ribs 9 is rectangular, but in order to reduce the resistance of the molten polymer during spinning, it is preferable to make it into a chevron shape or an arcuate shape.

The hollow fiber spinneret 5' obtained by the manufacturing method of the present invention has a core bar 7 inside the polymer discharge hole 3.
An arc-shaped reinforcing rib 9 is integrally provided on the upper surface of the connecting portion 8 of the core bar 7 and is connected to the inner peripheral surface of the middle part of the polymer introduction hole 2, so that the core bar 7 is firmly attached to the spinning hole 4.
Since the core bar 7 is held on the inner surface of the core bar 7, the core bar 7 does not deform at all even when subjected to the high heat of the molten polymer and high spinning pressure during spinning, and the core bar 7 does not sag or fall off even after long-term use. There is nothing to do. Therefore, the molten polymer discharged from the polymer discharge hole 3 has both ends of a C-shaped cross section welded immediately after spinning, so that the inner and outer circumferences are concentric and the thickness is uniform in the circumferential direction, as shown in Fig. 2. A normal hollow fiber 6 is obtained.

In the manufacturing method of the above embodiment, a hollow fiber spinneret 5' for melt spinning was made, but a hollow fiber spinneret 5'' for wet spinning may also be made as shown in FIGS. 6a and b. In this case. The polymer introduction hole 2' is formed in the shape of an inverted trapezoid, and the core bar 7 inside the polymer discharge hole 3
A reinforcing rib 9 projects from the upper opening edge of the polymer introduction hole 2' to the bottom surface.

Further, in the manufacturing method of the present invention, a solid spinneret having irregularly shaped polymer discharge holes 10 and 11 having protruding portions 10a and 11a on the inner surface as shown in FIGS. 7 and 8 can be easily manufactured. The protruding portions 10a and 11a of the polymer discharge holes 10 and 11 of the obtained solid yarn spinneret are held by the reinforcing ribs as in the previous embodiment, so that this solid yarn spinneret can be used for a long period of time. Even if the protruding portion 10a, 1
It is possible to obtain a solid yarn with a normal irregular shape without causing 1a to sag or fall off.

As detailed above, according to the spinneret manufacturing method of the present invention, the core metal inside the polymer discharge hole will never deform or fall off even after long-term use, and normal hollow fibers or irregularly shaped fibers will always be produced. An excellent effect is that a spinneret capable of spinning fibers can be easily obtained.

[Brief explanation of drawings]

Figures 1a and b are longitudinal sectional perspective views of the main parts showing the steps of a conventional manufacturing method for producing a hollow fiber spinneret, Figure 2 is a cross-sectional view of a normal hollow fiber, and Figure 3 is a conventional hollow fiber spinning A vertical sectional view of the main part showing a state in which the core metal inside the polymer discharge hole in the mouthpiece is deformed and sagging;
Figure 4a is a cross-sectional view of an abnormal hollow fiber spun from the polymer discharge hole in Figure 3, and Figure b is a cross-sectional view of an abnormal hollow fiber spun by polymer discharge from which the core has fallen off, as shown by the chain line in Figure 3. A cross-sectional view of a real yarn, FIGS. 5a and 5b are longitudinal sectional perspective views of essential parts showing steps of an embodiment of the manufacturing method of the present invention for manufacturing a hollow fiber spinneret, and FIGS. 6a and b
7 is a longitudinal sectional perspective view of a main part showing the steps of another embodiment of the manufacturing method of the present invention for manufacturing a hollow fiber spinneret for wet spinning, and FIGS. 7 and 8 are polymer discharge holes according to the manufacturing method of the present invention. It is a sectional view showing other examples. 1...Cap plate, 2, 2'...Polymer introduction hole,
3...Polymer discharge hole, 4'...Spinning hole, 5',
5″...Hollow fiber spinneret, 6...Circular hollow fiber,
7...Core metal, 8...Connection part, 9...Reinforcement rib, 1
0, 11...polymer discharge hole, 10a, 11a...
...Protruding parts. (The above is related to the present invention).

Claims (1)

[Claims] 1. A polymer introduction hole with a bottom is bored in the cap plate, and at the same time a reinforcing rib is provided protruding from the upper opening edge of the polymer introduction hole or the inner peripheral surface of the middle part to the bottom surface, and then a reinforcing rib is installed on the bottom surface of the polymer introduction hole. 1. A method for manufacturing a spinneret, which comprises forming a spinning hole by piercing a partially interrupted annular polymer discharge hole while avoiding the above.