JPS58197303A - Melt spinning method - Google Patents

Abstract

PURPOSE:To obtain uniform yarns having slight uneven denier and dyeing, by spinning synthetic fibers with a special spinning stack having openings for adjusting the air velocities of suction air and discharge air respectively to specific values. CONSTITUTION:Synthetic fibers are melt spun through a spinneret 1 at >=2,500m/min spinning speed by using a spinning stack 5 having a cooling air supply part 3 in the upper part, an opening 4 opening to a spinning chamber and a air discharge part 6 at the lowe part, and adjusting the air discharge rate with the air velocity at the openings adjusted to <=50cm/sec for the suction air and <=30cm/sec for the discharge air with the opening of air discharge holes perforated at the bottom of the spinning stack 5 adjusted to preferably 10-40%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for uniformly melt-spinning synthetic fiber yarn at a high speed of 4500 m7 minutes or more.

General K, the spinning tube used in melt spinning is placed at the bottom of the spinning device in order to stably cool the spun yarn while cooling and solidifying it while preventing disturbances in airflow from the outside.
A cylindrical body is installed directly in the cylinder, and a cup (-) having a guide hole (hereinafter, slit hole is also included) for converging and positioning the cooled and solidified yarn is provided at the lower end thereof.

The spinning speed in conventional melt spinning is t,oo.

Since the spinning speed was as low as about m/min, there were no major problems with the yarn even when the above-mentioned spinning cylinder was used. However, recently the spinning speed of yarn has increased to 11
When spinning began at high speeds of 500 m and 7 minutes,
Various troubles that never existed before have occurred! ! Ta. For example, when the spinning speed becomes extremely high as mentioned above, the airflow generated as the yarn runs increases, and this airflow collides with the cover at the bottom end of the spinning tube, causing turbulence in the airflow in the vicinity. K asked me to do it. Therefore, the thread □ is F of the spinning tube.
When the spinning shaft shakes near the end, the shaking is transmitted to the yarn running inside the spinning tube, causing the entire spinning tube to shake violently. As a result, the resulting yarn has the disadvantage of denier mottling and dyeing mottling. The spinning tube used for high-speed spinning of 2.500 ffI/min or higher is generally provided with a cooling air discharge hole at its F end.
3413, etc.), On the other hand, in high-speed spinning, minimizing the disturbance of the accompanying airflow accompanying the running of the yarn and making it close to a sifted % regularity * prevents yarn shaking and prevents the occurrence of denier unevenness and streaks. Therefore, it is necessary to minimize the pressure difference between the inside and outside of the spinning tube. One way to do this is to optimize the air flow rate in a closed spinning tube, but it is difficult to precisely control the air flow, and in practice it is difficult to control the air flow rate precisely. It is appropriate to eliminate the pressure difference between the inside and outside of the spinning cylinder by opening the part to the outside air and adjusting the amount of air that is insufficient by the airflow by letting the PK in or out.

Now, a part of this camphor spinning cylinder F part opens into the spinning chamber.
Use a spinning tube with an exhaust 11L section at the lower end 11,! 500
Melt spinning can be performed at speeds of m/min or more! When the amount of air discharged from the D end is increased, the amount of air sucked in from the spinning 1pH opening at the top increases, and only the accompanying flow from the upper part to the F direction accompanies the running of the yarn in the spinning tube duct, and the yarn Less shaking and denier spots.

A yarn with good drawability and few streaks can be obtained. However, in this case, since outside air is taken in from the top of the spinning tube, the physical structure of the yarn, such as the degree of orientation and crystallinity, is affected by atmospheric conditions such as the temperature and humidity of the outside air. Therefore, it is necessary to control the outside air to a constant temperature and humidity, but the opening at the top of the spinning tube is not in the spinning chamber, and there is no heat source such as a melter or spin block, so the atmospheric conditions here must be controlled. Throughout the year, it's just 1 leg apart! K, which controls IK, requires a large amount of energy and is economically unfavorable.

- If you reduce the amount of air exhausted from the bottom end and conversely exhaust the airflow from the upper spinner tube opening, it will not be affected by the atmospheric conditions of the outside air, but in this case, the inside of the spinner tube duct A phenomenon in which the airflow rises (that is, in addition to the yarn-associated airflow flowing from the top to the bottom, an upward airflow flowing from the bottom to the top occurs) is observed, and the airflow inside the spinning tube duct is disturbed, causing denier unevenness. , streaks occur.

The inventors of the present invention have arrived at the present invention as a result of intensive study on a method for spinning yarn that has smooth denier mottling and streaks and is unaffected by the atmospheric conditions of the outside air. It is something.

That is, the present invention uses a spinning tube that is provided with a cooling air blowing section and an opening that opens into the spinning chamber at the upper part, and an air exhaust section at the lower part, and melts synthetic fibers at a spinning speed of 4500 m 7 minutes or more. This melt spinning method is characterized in that during spinning, the wind speed at the cough opening is adjusted to 50 to 50 ees/second or less for intake air and 30 ees/second or less for exhaust air.

Next, one embodiment of the present invention will be described with reference to the drawings.

In the figure, (1) is the spinneret, (2) is the cooling chamber that blows out cooling air, (j) is the cooling air blower, and (4) is the opening that opens into the spinning chamber. A punching plate is used to prevent people from accidentally touching the yarn.

It is separated by a wire mesh screen and slit plate. (
5) is a spinning tube, (6) is an air exhaust part, (7) is a focusing guide hole, (8) is a cover, and (9) is a spun yarn. The example shown in the figure is a so-called side-blown spinning tube, and the air exhaust part (6) at the bottom end of the spinning tube consists of a number of holes, and the air flow accompanying the yarn naturally passes through these holes. Expelled outside.

By adjusting the aperture ratio of the nine exhaust holes drilled at the lower end of this spinning tube, the amount of exhaust air is adjusted, and the suction air speed and exhaust air speed from the upper opening of the spinning tube are adjusted within the above-mentioned appropriate range. be able to.

The spinning speed,
Although it varies depending on the amount of cooling air supplied and the denier of the spun yarn, it is usually sufficient to adjust the aperture ratio of the air exhaust part to 10 to 40. Any other method can be adopted as a means for adjusting the wind speed of the opening, and the method is not limited to the method of adjusting the aperture ratio described above.

Hereinafter, the present invention will be explained based on the *male side.

Using the side-blown spinning tube shown in the example diagram, the spinning speed was adjusted to sOOm.
/min, spinning tube blowout cooling air volume 3.5p/yd/min 75
A polyethylene terephthalate fiber of denier/36 filament (K 8111 after K stretching) was spun.

At this time, the amount of exhaust air was adjusted by changing the aperture ratio of a round hole drilled at the lower end of the spinning tube.

Here, the yarn fluctuation of the discharged yarn is "large J", "medium J", r-1
Divided into 3 levels: -J, large -1 is defective, -medium and 1-
"Small" was rated as good. U% is preferably 0.7- or less.

Streaks are judged visually using a 5-point method, and a score of 4.0 or higher is considered poor.

In order to investigate the influence of outside air, we conducted two experiments: one in which the front of the spinning machine in the spinning chamber was partitioned, and the internal atmospheric temperature was controlled at 40°C;
The difference in dyeing of the drawn yarn was investigated between the case where it was controlled at 0T: and the case where it was controlled at 0T:.

Differences in dyeing that can be clearly seen with the naked eye are classified as ``effects of outside air'', and turtles that are barely noticeable are classified as ``none''.

From the above results, it can be seen that the yarn spun by the method of the present invention has good denier irregularities and streak irregularities, and is not affected by the atmospheric conditions of the outside air.

[Brief explanation of drawings]

The figure is a sectional view of the spinning tube used in the present invention. (1) is a spinneret, (2) is a cooling chamber that blows out cooling air, (
3) is the cooling air blower, (4) is the opening, (5) is the spinning tube, (6) is the kamikaze part, (7) is the focusing guide hole, (8) is the cover, and (9) is the thread. be. Patent applicant Teijin Ltd.

Claims (1)

[Claims] 1 Cooling air blowing part in the t part and jsfl opening in the spinning ◆
When melt-spinning synthetic fibers at a spinning speed of 4,500 m/min or more using a spinning tube with a wind exhaust section at the bottom, the wind speed at the opening is 50 m/min in the case of suction wind. l) A melt spinning method in which the F1 discharge air is adjusted to 30 F/sec or less.