JPH0759765B2 - Method for producing polyester fiber - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyester fiber, and more particularly to a method for producing a polyester fiber which has good operability and economic efficiency and can obtain a uniformly drawn yarn.

(Prior art) Conventionally, as a polyester raw yarn for knitting, a take-up speed of 10
It is common to use a drawn yarn obtained by drawing an undrawn yarn drawn at 00 to 1500 m / min while heating it to the glass transition temperature (about 70 ° C) of the polyester fiber (hereinafter referred to as a separate drawing method). Sometimes called).

However, the polyester drawn yarn obtained by such a method has a large number of steps, resulting in high production cost.

Therefore, a direct spinning / drawing method in which the spinning step and the drawing step are directly connected is being put into practice.

In such a direct spinning drawing method, the same mechanical properties as those of the drawn yarn obtained by the conventional separate drawing method can be obtained, but the drawing must be performed at an extremely high speed as compared with the separate drawing method. In order to obtain a uniform drawn yarn without spots, it is important that the yarn is heated uniformly above the glass transition temperature.

Therefore, extremely advanced heat treatment technology is required, such as the need to develop a high-performance heating device.

In particular, when a plurality of yarns are drawn and drawn by using a heating roller as a heating device, if the take-up speed exceeds 4000m / min, the adjacent yarns come into contact with each other on the heating roller and a yarn break occurs. There is also the problem that it is easy.

A method capable of solving such a problem is proposed in JP-A-57-16913 and JP-A-57-16914.

This method is a method in which unstretched polyester yarn obtained by taking up at a take-up speed of 5000 m / min or more is subjected to a tension treatment of 20% or less without heating.

Although it is possible to prevent the yarn breakage due to the yarn contact on the roller by this method, the yarn is not heated at the time of stretching, so that the yarn breakage, fluff, etc. are still likely to occur.

(Object of the Invention) An object of the present invention is to directly heat and draw a polyester film obtained at a high take-up speed in a direct spinning and drawing method, in which the occurrence of yarn breakage and fluff is extremely small, and a uniformly drawn yarn has a high heating performance. It is an object of the present invention to provide a method for producing a polyester fiber obtained without using an apparatus.

(Structure) The present inventors do not require a high-performance heating device by drawing a polyester undrawn yarn obtained at a high take-up speed by jetting superheated steam to heat the yarn while heating the yarn. In addition, the present invention has been achieved as a result of a study conducted on the assumption that it can be stretched without causing yarn breakage and fluff.

That is, the present invention is to melt and discharge polyester, and then cool and solidify it, and then, without winding the yarn drawn by a take-up roller at 4000 m / min or more under non-heating, a fluid injection hole is formed on the wall surface. A plurality of holes are formed while inclining in the traveling direction, and the fluid is ejected through a jet nozzle in which the center lines of the respective fluid ejection holes intersect at one point, and at that time, superheated steam is ejected from the ejection holes to travel yarn. The method for producing a polyester fiber is characterized in that the polyester is stretched 1.05 to 1.5 times while being heated to a glass transition temperature or higher and then wound.

The present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the present invention.
The drawing is a vertical sectional view showing an example of a jet nozzle used in the present invention.

In FIG. 1, the polyester yarn (2) discharged from the melt spinning spinneret (1) was cooled and solidified while passing through a cooling cylinder (3), and then a prescribed amount of oil agent was applied by an oil supply device (4). Then, it is taken up by the first take-up roller (5). The taken-up yarn is continuously drawn while being heated by steam between the first take-up roller (5) and the second take-up roller (6) by the jet nozzle ( 7 ),
Then, if necessary, entanglement is given by the interlace nozzle (10), and then the material is passed through the guide (8) and wound by the winder (9).

In the present invention, the cooled and solidified polyester yarn (2) is taken up by the first take-up roller (5) at a non-heated take-up speed of 4000 m / min or more, followed by the first take-up roller (5) and the second take-up roller (5). It is important to inject the superheated steam between the take-up roller (6) and the jet nozzle ( 7 ) to heat the running yarn to the glass transition temperature or more and draw it 1.05 to 1.5 times.

Here, if the take-up speed is less than 4000 m / min, or if the yarn is taken while heating the first take-up roller (5), the yarn breakage is likely to occur frequently. Moreover, when the take-up speed is less than 4000 m / min, uneven dyeing occurs in the obtained drawn yarn.

The upper limit of the take-up speed is not particularly limited, but the higher the speed of the winder (9), the more expensive it is, and the workability such as threading property is deteriorated. Therefore, the upper limit of the take-up speed is 5000 m / min. It is preferable that

When the jet yarn ( 7 ) is stretched without jetting the superheated steam to the running yarns, the running yarns are below the glass transition temperature, so that the yarns are frequently broken and the resulting drawn yarns are unevenly dyed.

As such a jet nozzle ( 7 ), the one shown in FIG. 2 is preferable.

In FIG. 2, 11 is a yarn traveling nozzle, 12 is a yarn traveling nozzle wall surface, and 7'is a fluid injection hole.

As shown in FIG. 2, a plurality of fluid ejection holes (7 ') are formed on the wall surface (12) of the yarn traveling nozzle while inclining in the yarn traveling direction, and more preferably four or more holes are formed, and When the center lines of the injection holes intersect at one point, the yarn can be run at high speed without contacting the yarn running nozzle wall surface.

The inclination angle (θ) of the fluid injection hole (7 ′) is 60 ° or less,
It is preferably 45 ° or less.

The superheated steam jetted from the fluid jet hole (7 ') is such that the yarn temperature at the outlet of the jet nozzle ( 7 ) is heated to the glass transition temperature of the polyester fiber (about 70 ° C) or higher, preferably 130 to 220 ° C. Therefore, it is necessary to adjust the temperature and so on. For this reason, the temperature of superheated steam should be 250-550 ℃.
Is preferably set to, in the case of less than 250 ° C. tend to yarn temperature in Jetsutonozuru (7) is not increased sufficiently, when exceeding 550 ° C., it yarn in Jetsutonozuru (7) Tends to fuse or melt.

In the present invention, 1.05 to 1.50 while heating the running yarn in this way
Although it is drawn twice, if the draw ratio exceeds 1.5, many yarn breakages and fluffs occur, and the resulting dyed yarn has poor levelness. On the other hand, even when the draw ratio is less than 1.05, yarn breakage occurs frequently and a drawn yarn having sufficient physical properties cannot be obtained.

In the present invention as described above, the number of yarn turns of the first take-up roller (5) and the second take-up roller (6) shown in FIG. 1 can be less than 1, and the workability such as the thread catching property is improved. This has the advantages of reducing yarn breakage due to yarn runout and eliminating the need for a separate roller.

The term "polyester" used in the present invention mainly refers to a polyester composed of 90 mol% or more of ethylene terephthalate, but the amount of other components such as isophthalic acid, phthalic acid, oxybenzoic acid, and sulfonate is 10 mol% or less. It may be a compound, a monomer such as polyethylene glycol or tetramethylene glycol, or a low polymer thereof copolymerized or blended.

In addition, a small amount of a masking agent, an antistatic agent, a dye improving agent and the like may be added to the polyester.

(Operation) According to the present invention, by adopting a high spinning take-up speed, the required draw ratio is lowered, and further, superheated steam is used as a yarn heating source, and a jet nozzle as shown in FIG. 2 is used. As a result of uniformly heating and drawing the single fibers constituting the yarn, uniform drawing can be easily performed without using a high-performance heating roller as a heating device. It has the same mechanical properties as drawn yarn obtained by the drawing method, and has good levelness.

(Effects of the Invention) The polyester fiber obtained by the present invention has the same performance as the drawn yarn obtained by the conventional extra-drawing method, and has an excellent property that it can be used in all fields to which the conventional drawn yarn is applied. have.

(Example) Example 1 Using the apparatus shown in FIG. 1, polyethylene terephthalate was prepared with a die diameter of 0.2 mm, a number of holes of 36, a discharge rate of 35 g / min, and a spinning temperature of 300.
Melt-spin at 0 ° C., cool and solidify, apply oil agent, and take up by first take-up roller (5) rotating at peripheral speed shown in Table 1, and subsequently show first take-up roller (5) and Table 1. between the second take-up roller rotating at a peripheral speed (6), with superheated steam with Jetsutonozuru (7) of the fluid injecting hole (7 ') is shown in Figure 2 of 4 Ke Jetsutonozuru (7 ) The yarn temperature at the outlet was stretched while heating so that the yarn temperature was as shown in Table 1, and was wound by the winder (9) set to a winding speed 1% lower than that of the second take-up roller (6).

Table 1 also shows the peripheral speed ratio of the first take-up roller (5) and the second take-up roller (6), the process condition (whether or not the yarn breaks), and the yarn quality of the obtained drawn yarn. .

As is clear from Table 1, No. which does not satisfy the scope of the present invention.
Nos. 1,8,9,12,13 have poor process quality and the quality of the drawn yarn obtained is inferior.

Comparative Example The procedure was carried out under the same conditions as No. 9 except that the first take-up roller (5) was heated to 90 ° C and the second take-up roller (6) was heated to 150 ° C.

As shown in Table 2, the yarn quality and process tone of the obtained drawn yarn were inferior.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.
The drawing is a vertical sectional view showing an example of a jet nozzle used in the present invention. In the drawing, 5: first take-up roller, 11: yarn running nozzle 6: second take-up roller, 12: yarn running nozzle wall surface 7 : jet nozzle, 7 ': fluid ejection hole

 ─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-57-16913 (JP, A) JP-A-59-116414 (JP, A) JP-A-55-158324 (JP, A) JP-A-60- 94620 (JP, A) JP 59-116443 (JP, A) JP 56-107028 (JP, A) JP 53-38737 (JP, A)

Claims (1)

[Claims] 1. A polyester is melt-discharged and then cooled.
After being solidified, the yarn drawn by the take-up roller at a speed of 4000 m / min or more under non-heating is not wound once, and a plurality of fluid injection holes are opened on the wall surface while inclining in the yarn running direction, Moreover, while running in a jet nozzle in which the center lines of the respective fluid jet holes intersect at one point, superheated steam is jetted from the jet holes at that time to heat the running yarn to a glass transition temperature or higher and 1.05 to A method for producing a polyester fiber, which comprises drawing the film 1.5 times and then winding it.