JPH0816282B2 - Spinneret for melt spinning - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention provides a spinneret suitable for melt-spinning a thermoplastic polymer such as polyamide, polyolefin and polyester, and its purpose is to form a circular ring. A highly uniform synthetic fiber that cools evenly and effectively the yarn spun from a large number of arranged spinning holes and does not generate fused yarn, and has very few cross-section spots, orientation spots, etc. Is to get.

In particular, the present invention relates to a spinneret for spinning synthetic fibers as described above at a high speed and in a porous manner.

(B) Conventional technology In recent years, in order to improve the productivity of the equipment, the porosity and the speedup of the spinneret have been extensively studied, but the problem in this case is the cooling of the spun yarn. Is.

That is, the cooling step in melt spinning is an important step that significantly affects denier fluctuation rate, orientation degree, crystallinity, further the rate of fusion yarn, yarn breakage in the drawing step, occurrence of draw unevenness, etc. , It is necessary to cool uniformly.

Conventionally, there is a so-called horizontal blowing method as one cooling method, but this method has some drawbacks when cooling spots occur on the upwind side and the leeward side of the cooling air, and in particular, the tendency is promoted due to porosity. have.

As another method, when cooling a large number of yarns spun from a spinneret having a large number of spinning holes arranged in an annular shape, a cooling gas is blown from around the outer surface of the yarns. ing. In this method as well, as the die becomes more porous, cooling spots are generated on the upwind side and downwind side of the cooling air. In addition, since cooling air is blown from the outer peripheral direction, the collective shape of the entire yarns has an hourglass shape, and as a result, the single yarn gap is narrowed and the fusion phenomenon is likely to occur. It goes without saying that when this is a porous and high-speed spinning, fused yarns are more likely to occur.

As means for solving such a drawback, various equipment studies have been made in the cooling step. For example, as shown in (1) Japanese Examined Patent Publication No. 49-404, a cylindrical cooling air blowing device surrounding the spun yarn is provided so that the cooling air is blown from the outside to the center at the lower part of the spinneret. (2) Japanese Patent Laid-Open No. 52-156
As shown in Japanese Patent No. 15, a melt-spinning apparatus configured to cool a spun yarn by a cooling air radially outward from a central portion, (3) JP-A-51-116215 As shown in Fig. 1, various methods have been proposed, such as installing an alternating current body in the passage of the spinning traveling yarn below the spinneret surface. However, both of them have complicated structures, and it is difficult to observe the spinneret surface and the yarn immediately after spinning, it is difficult to insert a cooling air blowing device, and the spinneret is located at the center of the spinneret for cleaning the surface. There are many operational problems, such as the device being an obstacle and making it difficult to operate, and there are many defects in actual operation.

In view of such circumstances, the present inventors have used a spinneret having a large number of spinning holes (particularly 1000 or more holes), and an effective cooling method that is easy in operation without using a special cooling device. As a result of diligently studying, a large number of spinning holes, particularly 1000 or more, were uniformly cooled to obtain a synthetic fiber with high uniformity. In order to obtain the traveling air, the entrained airflow inside the traveling passage of the traveling yarn is released to the outside, and at the same time, the cooling air blown out from the cooling tube is allowed to easily reach the inside of the yarn, and thus the inside of the traveling yarn is It is important to reduce the temperature of the air flow in the passage, and basically, if the spinneret holes arranged in a plurality of annular rows are divided into 2 groups or more and 8 groups or less (preferably equal division). It is a good thing. That is, a non-perforated portion (non-perforated portion) is provided in the perforated annular row, and the non-perforated portion (non-perforated portion) includes two or more groups of the perforated annular row,
It was found that the structure was divided into 8 groups or less, and a patent application was previously filed for this (Japanese Patent Application No. 58-100037 (Japanese Patent Application Laid-Open No. 59-228011)).

By dividing the perforated part of the spinneret into several perforated groups as in this earlier application, the air flow between the inside and outside of the running yarn can be entered and exited without being substantially affected by the running yarn. Since such a passage is provided, as a result, the cooling air blown from the cooling cylinder can easily reach the inside of the yarn, and the airflow temperature inside the passage can be lowered. Particularly, in the case of increasing the spinning speed, the dividing method is particularly effective. That is, when high-speed spinning is performed in the so-called POY region where the winding speed is 3000 to 4500 m / min, or the so-called DSY region where the winding speed is 4500 to 5000 m / min, as compared to the desired UDY region where the winding speed is 1500 m / min or less, the yarn Cooling spots in the inner and outer layers of the are more likely to occur than in UDY. Therefore, the cooling air velocity tends to be increased in order to eliminate the cooling spots as much as possible. By the way, when a nozzle provided with a non-perforated portion (non-perforated portion) extending from the outermost peripheral annular row to the innermost peripheral annular row as shown in the prior application is used, cooling spots are not recognized, but cooling air is obtained although the effect is sufficient. And the turbulent airflow generated by the accompanying flow that flows at a high speed downstream, the yarn sway of the yarn around the inner layer part and / or especially around the non-perforated part,
It has been found that an irregular pulsation phenomenon appears and a fused yarn may occur.

(C) Problems to be Solved by the Invention As can be understood from the above, the prior art has a complicated structure in the spinning cooling section and has a large operational problem, and the actual operation operation is difficult, and the number of yarns is high. It was not preferred for speed spinning.

Therefore, the present invention provides a spinneret for performing multiple yarns and high-speed spinning using a spinneret having a large number of holes, which has a simple facility configuration, is easy to operate, and is capable of stable spinning. It is intended to be provided.

(D) Means and Actions for Solving the Problems That is, the present invention relates to a melt-spinning spinneret provided with a cylindrical cooling device surrounding a spun yarn, in which spinneret holes are bored in a plurality of annular rows. Arranged, all the annular rows of the outermost row or the inner 1 to 3 rows from the outermost row are perforated, and a non-perforated portion (non-perforated portion) is provided from the annular row to the innermost annular row, The melt-spinning die is characterized in that the perforated annular row is divided into two or more groups and eight or less groups by the non-perforated portion and satisfies the following expressions (1) to (3).

1.7 ≦ P ≦ 4 (1) 0.8 ≦ S ₁ / (S ₁ + S ₂ ) ≦ 0.95 (3) However, P; Distance between holes in innermost row (mm) D ₁ ; Outermost diameter of hole array (mm) D ₂ ; Outermost diameter of hole array ( mm) H; Number of holes (ke) S ₁ ; Area of perforated part (cm ² ) S ₂ ; Area of non-perforated part (non-perforated part) (cm ² ) When it is 9 or more, not only the passage of the air flow becomes too small to be meaningless as the passage of the air flow, but also the turbulence of the air flow such as cooling air occurs, and as a result, the yarn is shaken and the fused yarn is likely to occur, which is not preferable. . Therefore, the perforation group is preferably 2 or more groups and 8 or less groups, and more preferable division is to set the perforation groups to 3 to 5.

In such a divided arrangement of the perforation groups, the distance P (mm) between the holes in the innermost peripheral row that minimizes the hole distance is 1.7 mm or more and 4 mm.
The following are preferred. If it is smaller than 1.7 mm, the pore gap is too narrow to perform stable spinning, and the uniform effect is not obtained. Conversely, 4m
If it is larger than m, the purpose of porosity cannot be achieved, which is not preferable.

Furthermore, in the present invention, as the value corresponding to the perforation density of the spinning holes formed in the plurality of annular rows, the number of holes is set so as to satisfy the above formula 9 ≦ 400H / π (D ₁ ² −D ₂ ² ) ≦ 35. It is important to decide H. 40
When 0H / π (D ₁ ² −D ₁ ² ) is less than 9, the purpose of porosity cannot be achieved, which is not preferable, and when it is more than 35, satisfactory spinning cannot be performed and a uniform cooling effect is not obtained.

The ratio of the non-perforated part (non-perforated part) to the perforated part is the area of the perforated part S ₁ (cm ² ) and the area of the non-perforated part (non-perforated part) S ₂ (c
It is more preferable to provide a non-perforated portion (non-perforated portion) so as to satisfy the relationship of 0.8 ≦ S ₁ / (S ₁ + S ₂ ) ≦ 0.95 with respect to m ² ). Here, if S ₁ / S ₁ + S ₂ is smaller than 0.8, it is preferable from the viewpoint of cooling, but the area of the perforated portion occupying the area of the die is small, and high productivity cannot be expected. On the contrary, S ₁ / (S ₁ +
When S ₂ ) is larger than 0.95, high productivity can be expected, but uniform cooling cannot be obtained, and as a result, it becomes difficult to obtain a uniform yarn. The more preferable range is 0.85 ≦ S ₁ / (S ₁ + S) ≦ 0.92
Is.

The number of spinning holes arranged is preferably 8 rows or more for high productivity and uniform cooling, but if it exceeds 20 rows, it is not preferable in terms of uniform cooling, and 8 to 20 rows are preferable.

Further, in the present invention, the entire annular row from the outermost annular row to the innermost annular row is not divided into 2 to 8 groups, but the outermost annular row or the annular rows of 1 to 3 rows inside the outermost annular row are All the spinning holes are drilled, and the inner ring row is 2 to
Dividing into 8 groups.

The present invention will be described below with reference to the drawings, but the drawings are examples of the present invention and the present invention is not limited thereto.

FIG. 1 is a schematic view of a spinneret showing an embodiment of the present invention. In FIG. 1, reference numeral 1 is a mouthpiece main body, and a hole 12 for attaching the mouthpiece is provided in a central portion of the mouthpiece body, and is supported by a breaker plate or the like at the time of assembling into the pack 11 via bolts. Reference numeral 2 indicates a spinning hole formed in the spinneret, which is formed on the array row 4 with a constant gap. In this figure, the number of arrays is shown as a four-column array for convenience, but the number of arrays is not limited as long as it is 8 to 20 as described above. 3 shows a non-perforated part. This figure is an example of a die divided into four, and there are four non-perforated portions (non-perforated portions). Other first
In the figures, D ₁ is the outermost diameter of the hole arrangement, D ₂ is the innermost diameter of the hole arrangement, S ₁ is the area of the perforated portion, and S ₂ is the area of the partition portion.

FIG. 2 is a conceptual diagram showing a state of spinning using the spinneret according to the present invention.

Reference numeral 1 denotes a spinneret main body, and a spun yarn 6 discharged from the spinneret hole is cooled and solidified by cooling air blown from a cooling device 5. Then, after being focused by the guide 7 and applied with the oil agent by the oil agent applying device 8, the traveling direction is changed via the direction changing roller 9 and then the oil agent is taken out. On this occasion,
The non-perforated portion 3 of the die of the present invention serves as a passage for the air flow. That is, the cooling air blown out from the cooling cylinder can easily reach the inside, and at the same time, the associated airflow inside the passage of the traveling yarn is discharged to the outside of the yarn through this passage. Thus, the temperature of the air flow in the internal passage of the running yarn is lowered, the delay of cooling the inside yarn is eliminated, and uniform cooling is possible.

(E) Example In order to more specifically describe the effect of the present invention, an example will be shown below. The quality of the test results was comprehensively judged from (1) the occurrence of yarn breakage during spinning, (2) the occurrence of fused yarn, and (3) cross-section uniformity of the spun raw yarn after take-up.

 The evaluation was carried out according to the following criteria.

(1) Spinning tone ○ Mark-The number of times of yarn breakage is 1 or less in 4 hours of spinning. △ Mark-The number of times of yarn breakage is 2 to 5 times. X-The number of times of yarn breakage is 6 times or more. Take micrographs of four spinning yarns at 50m intervals,
Count the number of fused yarns generated.

○ Mark-fusing yarn generation is 0 △ Mark-fusing yarn generation is 2 to 4 × Mark-fusing yarn generation is 5 or more (3) Cross-section uniformity ○ mark-Following The variation given by the formula is 4% or less. △ -The above-mentioned variation is 4.1% to 7.5% × -The above-mentioned variation is 7.5% or more. The diameter d is measured. The fluctuation rate x is x = σn / × 10
It is given as 0. Here, the average value of the cross-sectional diameter and the standard deviation σ
n is Given in.

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.64 measured at 30 ° C. using an equal weight mixed solvent of phenol and tetrachlorethane was spun using a spinneret (spindle diameter 200 mmφ) having a spinning hole of 0.2 mmφ. Spinning was performed at a temperature of 285 ° C. and a take-up speed of 1200 m / min, and the discharge amount was adjusted so that the single yarn denier of the drawn spinning yarn became 4.0 denier. The spinneret used at this time has 12 holes and the total number of holes is 15.
00H / weight, and the form of the die used was that shown in Table 1.

A cooling device used in spinning was a cylindrical type, and the cooling conditions were fixed to the following conditions for the test.

(1) Cooling air blowing position: 30 mm below the spinneret (2) Cooling air blowing surface inner diameter: 235 mm (3) Cooling air blowing surface length: 250 mm (4) Cooling air temperature; 25 ° C (5) Cooling Wind speed; 0.75 m / sec Test results are shown in Table 1.

Further, the oil agent was applied by using an ordinary oiling roller.

Of the test Nos., 2 to 5 were within the scope of the present invention, and good results were obtained. On the other hand, Test No. 1 was a spinneret that did not divide, there were many fusion yarns, and the cross-section uniformity was also poor, so fluff and winding frequently occurred in the drawing process. I couldn't get a normal product. Further, Test No. 6 is an example of splitting exceeding the upper limit of the present invention, and the fused yarn due to turbulence of the air flow during spinning,
Frequent single yarn breakage made it impossible to achieve satisfactory spinning.

Example 2 Polyethylene terephthalate having an intrinsic viscosity of 0.64 measured at 30 ° C. using an equal weight mixed solvent of phenol and tetrachlorethane was spun using a spinneret (spinner diameter 200 mmφ) having spinning holes of 0.25 mmφ. The yarn was taken at a temperature of 290 ° C. and a take-up speed of 4500 m / min, and the discharge amount was adjusted so that the single yarn denier of the drawn spinning raw yarn was 2.3 denier. The spinneret used at this time had 13 or 15 holes.
The pitch between rows is 1.8 mm, the hole gap in the innermost row is 1.94 mm, and the total number of holes in the die is 3150 holes. This base 2730
The holes were filled with tapered aluminum pins and subjected to a test. The form of the base is Table 2 and 3
As shown in the figure.

A cooling device used in spinning was a cylindrical type, and the cooling conditions were fixed to the following conditions for the test.

(1) Cooling air blowing position; 30 mm below the spinneret (2) Inner diameter of cooling air blowing surface: 235 mm (3) Length of cooling air blowing surface: 300 mm (4) Cooling air temperature; 25 ° C (5) Cooling Wind speed; 1.2m / sec Test results are shown in Table 2.

Further, the oil agent was applied by using an ordinary oiling roller.

Of the test Nos., Nos. 8, 10, 12, and 13 were within the scope of the present invention, and good results were obtained. On the other hand, in the No. 7 test in which the non-perforated part was not provided, the inner yarns were heavily fused and it was impossible to perform satisfactory spinning. Further, in Nos. 9 and 11 in which the non-perforated portion (non-perforated portion) was provided from the outermost peripheral row, an unfavorable phenomenon such as an irregular pulsation phenomenon of the internal yarn and a fusion of the yarn occurred immediately near the non-perforated portion. Further, in Test No. 13 which exceeds the upper limit of splitting of the present invention, normal spinning was impossible due to the turbulence of the air flow.

(E) Effect of the invention As shown in the examples, the present invention can maximize its effect particularly in multi-thread and high-speed spinning, and by improving only the spinneret, multi-fiber and high-speed spinning can be achieved. It is capable of uniform cooling, does not require an extra cooling device or auxiliary equipment, and has the same operability as the conventional spinning process, enabling highly stable operation of multiple yarns and high-speed spinning. It is an excellent one in practice.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing an embodiment of a melt-spinning spinneret used in the present invention, and FIG. 2 is a schematic view showing one state when spinning is performed using the spinneret according to the present invention. 3 and 4 are partial schematic views of the spinneret showing the relationship between the spinning holes and the non-punching portion. 1; Spinneret, 2; Spinning hole, 3; Non-punching part (non-punching part), 4; Spinning hole array row, 5; Cooling device, 6; Yarn, 7; Guide, 8; Lubricant supply device, 9 ; Direction change roller, 10; clasp pack, 11; bolt hole for clasp attachment

Claims (1)

[Claims] 1. A melt-spinning spinneret provided with a cylindrical cooling device surrounding a spun yarn, wherein spinneret holes are arranged in a plurality of annular rows on the spinneret surface, and the outermost row or the innermost row 1 is located inside the outermost row. All of the three annular rows are perforated, and non-perforated portions (non-perforated portions) are provided from the annular rows to the innermost peripheral annular row, and the non-perforated annular rows form two or more groups of eight groups. A spinneret for melt spinning, which is divided into the following and satisfies the following formulas (1) to (3). 1.7 ≦ P ≦ 4 (1) 0.8 ≤ S ₁ / (S ₁ + S ₂ ) ≤ 0.95 (3) where P: Innermost row hole spacing (mm) D ₁ ; Hole array outermost diameter (mm) D ₂ ; Hole array innermost diameter ( mm) H; Number of holes (K) S ₁ ; Area of perforated part (cm ² ) S ₂ ; Area of non-perforated part (non-perforated part) (cm ² )