JPS5851042B2 - spinneret - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a spinneret, and in particular, the length L of the spinning hole (the straight part through which the polymer passes through a liquid reservoir and has a uniform inner diameter) is significantly long, and when the diameter of the spinning hole is D = 0.05 to 2.0 mx, L
'2500D+200, ie, L is 225111 or more (therefore, L/D is 600 or more).

The length L of the spinning hole in the conventionally widely used spinneret
is about several to lO several n, for example,
Publication No. 492 states that L is l 2 II s 6tsm, 2
An example of m is shown, and when L is 121 m, D is 0.6
(L/D=20), 0.41ts (L
/D=15), and 0.4 trend (L/D=5) for 2B.

As another example, in Japanese Patent Publication No. 44-16804, L
is 0.90 iti, D is 0.40tttvt (L /
D#2) is described.

Even in commonly used spinnerets, D is generally 0.2 to 0.3 m11. L is up to about 10 U at most, and there is no example of the use of a spinneret with a very long spinning hole such as L of 225 m or more as in the present invention.

However, a spinneret having an L/D of 100 or more is known in the literature (Japanese Patent Publication No. 7413/1983).

According to this patent, aiming at latent crimpable fibers, I,
/D > 100 and a spinneret having a deformed (circular) spinning hole with an enlarged part biased toward the discharge surface side of the spinning hole is described, and no other literature has been found, and no such spinning hole is actually used. It is true that no large spinneret is used.

Although it is said in this document that L/D>100, D is generally 0.2 to 0.3 mm, and in rare cases it is around 0.6 mm, but even if D2 is 0.6 mm, L at that time is 6
0 mm (or more), and this does not imply a range of 225 tit or more as in the present invention.

Moreover, this document only states that fibers with latent crimpability can be obtained using the spinneret, and that fibers with excellent mechanical properties that do not require drawing, which are the effects of the present invention described below, can be obtained only by the spinning process. There is no indication that it will be obtained immediately.

The above is the background of the technology related to L or L/D that is similar to the present invention, but the present invention was discovered in a completely different area that could not be considered with the common sense of conventional spinning technology.

That is, the main aim of the present invention is to obtain a fiber whose yarn immediately after spinning has various mechanical properties that can be practically used without drawing. Another aim is that since the yarn is already solidified immediately after spinning, the yarns do not stick to each other immediately after spinning, which makes it possible to install many spinning holes adjacent to each other per spinneret. This leads to improved productivity, and another additional effect is that by not performing a drawing operation, the yarn surface is kept in the same Japanese-like shape as spun, and the smoothness of the yarn surface is not improved. It is possible to go.

Nowadays, when manufacturing synthetic fibers, it is desired to perform as few steps as possible and to implement them rationally. For example, in order to eliminate the drawing step in the spinning process, the spinning speed (winding speed) should be reduced to 3. 000~3.500771/
A method has also been adopted in which the stretching is carried out at a stretching speed of about 100 min and then no substantial stretching is applied.

Also, as a known document, polyester is 4,750 m/
There are also reports of attempts to spin fibers at high speeds such as min or higher and use them as ordinary fibers as they are (Japanese Patent Publication No. 35
-3104 publication).

Furthermore, a recent known document (Japanese Patent Publication No. 53-27367) even proposes spinning and winding at 6,000 ψin or more.

These documents aim at simplifying processes and are one technique that suggests the direction of industry.

However, the problem with these ultra-high speed spinning systems is how to adapt the structure of the winding machine to support high speeds.

At present, machines that can be used for winding of about 3,000 m/min have been completed and put into practical use, but when this increases to 5 to 6,000 m/min or more, the design and cost of the winding machine become major factors. Therefore, it is questionable whether the advantage of omitting the stretching process is viable.

Such high-speed spinning methods, which have begun to be adopted in recent years, account for only about 10% of the manufacturing methods for synthetic fibers, especially synthetic fibers obtained by melt spinning, and account for the other 90%.
This is a low-speed spinning method with a spinning speed of about 5 to 600 m/min.

In view of this reality, the inventor of the present invention did not require any equipment improvement to increase the speed of the winding machine; rather, winding could be carried out at a lower winding speed than the conventional speed, and simply by changing the speed of the spinneret. By adopting a completely new structure, the cost factor is kept to a minimum, thereby creating a yarn that does not require a drawing process immediately after spinning.

That is, the characteristics of the spinneret according to the present invention are as follows:
As mentioned above, the diameter of the spinning hole is set to 0.05 to 2. When turned on, the length L is L>500D+200, that is, 22
．． The point is that it is 5 mm or more.

Then, finding L/D from the relationship between D and L, L/D>6
00, and L in the above-mentioned conventionally known document
/D>lOO, this is an area that cannot be easily considered.

As described above, in the present invention, since L is extremely large with respect to D, such as 600 or more, a stretching operation is further added because the polymer is effectively given a stretching effect when passing through the spinning hole. It is considered unnecessary.

Furthermore, when using the spinneret of the present invention41, the high molecular weight polymer is easily located in the center of the spinning hole and the low molecular weight polymer is located in the surrounding area due to the separation effect, so even if a single polymer is spun, it will look like a kind of composite fiber. It shows a typical fiber morphology.

This can be said to be a more preferable spinneret for spinning so-called composite fibers from composite polymers.

L in the spinneret of the present invention should always satisfy L≧500D+200 in relation to D, more preferably L>400D+350, especially L with L/D of about 2,500 or more. It is preferable from the viewpoint of the mechanical properties of the spun yarn.

Generally speaking, the longer L is, the better it is for the properties of the yarn, but if it is too long, the spinning pressure will be too high and the manufacture of the spinneret itself will be complicated, so L < 300.
Preferably it is D+940.

Therefore, the upper limit of D that can be adopted in the present invention is 2.0 mm.
It is also desirable to keep it within about 1,500 degrees.

D in the present invention is within 1.0 mm, particularly 0.2 to 0.
4 mπ is common.

The spinneret of the present invention that satisfies these conditions is the above-mentioned L
It can be easily obtained by forming a single spinning hole with a metal capillary satisfying the relationship of

The structure of such a spinneret and its manufacturing method are completely unprecedented.

The spinning hole of the present invention is not limited to a circular shape, but may have an irregular shape or may be hollow.Although the following explanation will be given only to an example in which the spinneret of the present invention is applied to a melt spinning method, basically it is applicable to at least a dry spinning method. It is applicable to

Therefore, it is of course applicable to a spinning method in which two or more types of polymers are mixed and simultaneously introduced into the spinning hole.

According to the research conducted by the present inventors, the spinning speed can be reduced to just a few m/min using a multi-hole spinneret that satisfies the conditions of the present invention.
By melt spinning at a spinning speed of 3. without further drawing. Spun threads before and after OOOm/min (
However, it has been found that it is possible to obtain fibers having physical properties comparable to those obtained using a conventional method using a spinneret with L/D of about 5 to 20.

Another feature of the present invention is that the yarns are solidified immediately after spinning, so they do not stick to each other, and the surface smoothness of the yarns is compared to that of ordinary drawn fibers. In other words, it is inferior in that there are irregularities on the entire surface.

The surface of ordinary drawn fibers, especially fibers obtained by melt spinning, is clear, and many attempts have been made to form surface irregularities by removing surface polymers and inorganic additives by treating them with alkali or formic acid. The reality is that there are.

Since the hygroscopicity, dye exhaustion, coloring properties, etc. of the fibers vary greatly depending on whether the surface is smooth or not, it is desirable to provide the fiber surface with irregularities, if possible, as well as fine irregularities.

According to the present invention, since no stretching is performed, fibers having some degree of irregularities on the fiber surface can be obtained without subjecting the spun yarn to any post-treatment such as alkali treatment.

However, when no inorganic substance is added to the repolymer that has not been subjected to alkali treatment in the spun yarn of the present invention, the surface irregularities cannot be said to be fine. Should be used in conjunction with treatment.

The present invention will be explained below with reference to Examples, but it goes without saying that the present invention is not limited to the Examples.

Examples 1 to 2 and Comparative Examples 1 to 2 Polyethylene terephthalate having [η)=0.70 was spun using a spinneret having 150 spinning holes under the following conditions, with L being varied.

The results are shown in Table 1.

As is clear from this result, when using the spinneret of the present invention, the winding speed is only about 1 m/in in, compared to 2,500 to 3,000 m/min when using the conventional spinneret.
Although fibers with the same quality as the yarn obtained by the winding method of n were obtained, when using a spinneret that does not meet the conditions of the present invention, even if the winding speed was set to 500 ml/min. Only a yarn having a strength of only about 50% of the fiber of the present invention can be obtained, and the elongation and hot water shrinkage rate at that time are also large and clearly inferior to the yarn quality of the present invention.

Claims (1)

[Claims] 1. When the length of the spinning hole is L-1 and the diameter of the spinning hole is D-, 2.0≧D≧0.05. A spinneret characterized in that L≧500D+200. 2. The spinneret described in the preceding paragraph, characterized in that D<1.0. 3 In claim 1 or 2, 0.2<D
A spinneret characterized in that <: 0.4. 4 In any one of claims 1 to 3,
A spinneret characterized in that it is 00D+940.