JPH0362802B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a spinneret used in producing bulky deformed hollow fibers by melt spinning a thermoplastic polymer compound.

(Prior Art) Conventionally, as a spinneret for melt spinning irregularly shaped hollow fibers, a plurality of slits 1, 1', 1'', 1 are used as shown in FIGS.
A gap 2, 2', 2'', 2 between each adjacent end
, and arranged to form a closed loop, each slit 1, 1', 1'', 1 has a linear slit 3, 3', 3'', 3 extending radially outward.
It is known to have a series of

In this spinneret, each slit 1, 1',
The molten polymer discharged from the gaps 2, 2', 2'', 2 expands due to the balance effect and is discharged from the gaps 2, 2', 2'', 2.
In this process, the adjacent ends are fused together to form a hollow fiber while sucking air.

However, in such a conventional spinneret, since each slit 1, 1', 1'', 1 is connected with a linear slit 3, 3', 3'', 3 extending radially outward, Shape slit 3, 3', 3'', 3
Due to the action of the polymer discharged from the slits 1, 1', 1'', 1, an outward expanding force acts on the molten polymer discharged from the slits 1, 1', 1'', 1, and the adjacent ends of the discharged polymer are fused together in the gap. Therefore, as shown in FIG. 6, a defective fiber called a so-called broken hollow fiber, in which a part of the hollow portion is broken, is likely to be produced.

In order to prevent the occurrence of such broken hollow fibers, the gaps 2, 1, 1, 1, 1, 1, 1, 1,
2′, 2″, 2 should be made as narrow as possible,
If the gaps 2, 2', 2'', 2 are made too narrow,
There is a natural limit to this because the spinneret may be damaged due to the pressure of the molten polymer applied to the spinneret during melt spinning.

(Object of the Invention) The object of the present invention is to solve the problems of the conventional spinnerets for irregularly shaped hollow fibers, and to create irregularly shaped hollow fibers that do not cause broken hollow fibers and are not damaged by the pressure of molten polymer during spinning. An object of the present invention is to provide a spinneret for yarn.

(Structure of the Invention) The present invention is a spinneret for producing a deformed hollow fiber having one hollow portion in the center, wherein a plurality of slits are arranged with a space between adjacent end portions of the plurality of slits. A linear shape that is arranged so as to form a closed loop with slits, and protrudes radially from the inside of the closed loop to the outside beyond the slits, giving a protruding part to the inside and outside of the formed hollow fiber. This is a spinneret for irregularly shaped hollow bodies, which is characterized by having slits carved therein.

Hereinafter, the spinneret of the present invention will be explained in detail with reference to the drawings. 1a-c and 2 are enlarged plan views showing some examples of the spinneret of the present invention,
A plurality of slits 1, 1', 1'', 1 are arranged so as to form gaps 2, 2', 2'', 2 between their adjacent ends and to form a closed loop, Straight slits 4, 4', 4'', 4 are disposed extending radially from the inside of the closed loop to the outside through 2, 2', 2'', 2.

The slits 1, 1', 1'', 1 must be arranged so that a plurality of them are combined to form a closed loop, and when a closed loop is formed with one slit, the cap member inside the closed loop is held. The number of slits 1, 1', 1'', 1 is between 2 and 6. It is particularly preferable to use 2 to 4 pieces. Slit 1, 1', 1'', 1
can be of any shape, such as an arc shape as shown in FIGS. 1a and 2, a hook shape as shown in FIGS. 1b and c, or a linear shape.

Furthermore, straight slits 4, 4', 4 extend radially from the inside to the outside of the closed loop through the gaps 2, 2', 2'', 2 between adjacent ends of the slits 1, 1', 1'', 1. '', 4 is provided, but this gap 2,
2', 2'', 2 are preferably selected within the range of 0.2 to 0.4 mm, and the width of the linear slits 4, 4', 4'', 4 is preferably selected within the range of 0.05 to 0.3 mm.
1', 1'', 1 end and gap 2, 2', 2'', 2
It is preferable that the gap d between the straight slits 4, 4', 4'', and 4 passing through the sides of the slits is 0.2 to 0.4 mm.
Furthermore, it is desirable that the protruding length l of the linear slits 4, 4', 4'', 4 from the slits 1, 1', 1'', 1 to the inside of the closed loop is approximately 0.5 to 1.5 mm. The ends of each slot should not touch each other.

The spinneret of the present invention can be applied to melt-spinning thermoplastic polymers, and is particularly effective for melt-spinning polyesters and polyamides.

(Function and Effects of the Invention) Generally, the molten polymer discharged from the slit expands in the width direction of the slit and the length direction of the slit due to the ballast effect. Next, this swelling is
Due to surface tension, it increases in the slit width direction,
The length of the slit decreases.

In the conventional spinneret shown in Figs. 4 and 5, the molten polymer discharged from the ends of the slits 1, 1', 1'', and 1 expands and then expands due to surface tension. The swelling is reduced, and furthermore, due to the action of the polymer discharged from the linear slits 3, 3', 3'', 3, the slits 1, 1',
Coupled with the force acting on the polymer discharged from 1'', 1 to expand outward, the gap 2, 2',
In the case of 2'', 2 parts, adjacent ends of the discharged polymer are not fused together, and a broken hollow fiber as shown in FIG. 6 is often formed.

On the other hand, in the spinneret of the present invention, the linear slits 4, 4', 4'', 4 are replaced by the slits 1, 1',
1'', 1, the gaps 2, 2', 2'', 2
It is located through. Therefore, no outward expanding force acts on the polymer discharged from the slits 1, 1', 1'', 1.Furthermore, the molten polymer discharged from the ends of the slits 1, 1', 1'', 1 , once expanded, even if the expansion is reduced due to surface tension, the linear slits 4, 4',
The molten polymer discharged from the gaps 2, 2', and 4 expands in the width direction, so the molten polymer discharged from the gaps 2, 2', and
2'', 2 parts, the polymer is very easily discharged from the mutually adjacent ends of the slits 1, 1', 1'', 1 and the linear slits 4, 4', 4'', 4 disposed therebetween. As a result, completely irregularly shaped hollow fibers as shown in Figure 3 can be stably obtained, and during spinning, the polymer temperature, spinning speed, polymer discharge amount, spun yarn cooling conditions, etc. Even if the conditions change, broken hollow fibers as shown in FIG. 6 do not occur.

Furthermore, in the spinneret of the present invention, since gaps 2, 2', 2'', 2 are formed between the adjacent ends of the plurality of slits 1, 1', 1'', 1, naturally, The number of gaps 2, 2', 2'', 2 is also plural, so that sufficient strength of the spindle can be ensured, and the spindle will not be deformed by the pressure of the discharged polymer during spinning.

(Example) Hereinafter, the spinneret of the present invention will be further described with reference to Examples.

Example Using a spinneret with 68 spinneret holes of the shape shown in Fig. 2, the intrinsic viscosity (in m-cresol, 25°C
Nylon 6 with a diameter of 1.30 (measured at
Spinning was carried out at a discharge rate of 400 g/min, and spinning was carried out at a spinning speed of 900 m/min while cooling with a cooling air flow rate of 5 m ³ /min. The diameter of the cap hole slit 1, 1', 1'' is 1.5mm.
The slit width is 0.2 mm, the length of straight slits 4, 4', 4'' is 2 mm, the slit width is 0.2 mm, and the edges of slits 1, 1', 1'' and the gap 2 , 2′, 2″ straight slits 4, 4′,
The distance d between the slits 4'' and the side portions was 0.3 mm, and the length l of the inward protrusion of the linear slits 4, 4', 4'' from the slits 1, 1', 1'' was 0.5 mm.

The spun yarn was drawn 3.3 times by a conventional method, and
A drawn yarn of denier/68 filament was obtained. There was almost no occurrence of fuzz or lapping during drawing, and the strength during drawing was 3.2 g/de, the elongation was 38%, and no breakage in the hollow part was observed in any of the single yarns, as shown in Figure 3. It was a good hollow fiber.

Comparative Example A spinneret having 68 nozzle holes as shown in FIG. 5 was used, and other conditions were the same as in the example.
Stretched.

The slits 1, 1', 1'' of the cap hole are bored on concentric circles with a diameter of 1.5 mm, the slit width is 0.2 mm, the length of the linear slits 3, 3', 3'' is 1 mm, and the slit width is 0.2 mm. The distance between gaps 2, 2', and 2'' was 0.3 mm.

The obtained drawn yarn consists of 10 out of 68 filaments.
Fractures in the hollow portions as shown in FIG. 6 were observed in the filament, and fuzz and lapping occurred frequently during stretching.

[Brief explanation of drawings]

1 and 2 are enlarged plan views showing an example of the spinneret of the present invention, FIG. 3 is an enlarged cross-sectional view of a yarn obtained by spinning with the spinneret of FIG. 2, and FIG. FIG. 5 is an enlarged plan view showing an example of a conventional spinneret;
FIG. 6 is an enlarged cross-sectional view of a yarn obtained by spinning using the spinneret shown in FIG. 1, 1', 1'', 1...slit, 2, 2',
2″, 2...gap, 4, 4', 4″, 4... linear slit.

Claims (1)

[Scope of Claims] 1. A spinneret for producing irregularly shaped hollow fibers having one hollow portion in the center, the spinneret comprising a plurality of slits with spaces between adjacent end portions of the plurality of slits. A linear slit is disposed so as to form a closed loop with the slit, and protrudes radially from the inside of the closed loop to the outside beyond the slit, and provides a protruding portion to the inside and outside of the formed hollow fiber. A spinneret for irregularly shaped hollow fibers characterized by being engraved. 2. The spinneret for irregularly shaped hollow fibers according to claim 1, wherein the number of slits forming a closed loop is 2 to 6.