JPS59228011A - Spinneret for melt spinning - Google Patents

Abstract

PURPOSE:To manufacture multi-filament having extremely uniform physical properties, without causing the fusion of the filaments, by boring the spinning nozzles along plural circularly arranged rows to a spinneret, wherein the spinning nozzles are divided into 2-8 groups by the plural radially arranged unbored region, and selecting the distance between the nozzles, the maximum diameter and the minimum diameter to specific respective values. CONSTITUTION:A number of spinning nozzles 2 are bored to the spinneret 1 along plural (3 in the cse of the figure) circular rows. The circular rows are divided into 2-8 groups by the plural unbored regions (parts devoid of nozzle) common from the outermost row to the innermost row. The distance between the nozzles 2 at the innermost row is selected to 1.7-4mm.. The diameter D1 (mm.) of the innermost row, the diameter D2 (mm.) of the outermost row, and the total number of the spinning nozzles (H) is made to satisfy the formula I . The area S1 of the bored region and the area S2 of the unbored region preferably satisfy the condition of the formula II.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a spinneret suitable for melt spinning thermoplastic polymers such as polyamide, polyolefin, and polyester. To uniformly and effectively cool spun tip yarns, thereby preventing generation of fused yarns, and obtaining highly uniform synthetic fibers with extremely few cross-sectional irregularities, orientation irregularities, etc.

In particular, the present invention relates to a multi-hole spinneret for multi-hole spinning of synthetic fibers as described above.

In recent years, in order to improve equipment productivity, there has been a lot of research into making spinnerets porous, but the problem with this is the cooling of the spun yarn, that is, the cooling process in melt spinning. This is an important process that significantly affects the denier fluctuation rate, degree of orientation, crystallinity, as well as the incidence of fused yarn, yarn breakage in the drawing process, and the occurrence of drawing unevenness. is necessary.

One conventional cooling method is the so-called cross-blowing method.
This method has the disadvantage that cooling spots occur on the windward and leeward sides of the cooling air, and this tendency is particularly exacerbated by the increased porosity.

Another known method is to blow cooling gas from around the outer surface of the yarn when cooling a large number of yarns spun from a spinneret with a large number of spinning holes arranged in an annular shape. ing. Even in this method, as the cap becomes more porous, cooling spots will occur on the windward and leeward sides of the cooling air. Moreover, since the cooling air is blown from the outer circumferential direction, the collective form of the yarns as a whole becomes drum-shaped, resulting in a narrowing of the single yarn gap and a disadvantage that the fusion phenomenon tends to occur.

As a means to solve these drawbacks, various equipment studies have been made in the cooling process.

For example, (1) K as shown in Japanese Patent Publication No. 49-404.

A device in which a cylindrical cooling air blowing device surrounding a spun yarn is provided to blow cooling air from the outside into the inside, and at the same time a suction device is provided in the lower central part of the spinneret to suck out hot air; As shown in No. 15615/1983, a melt spinning apparatus configured to cool the spun yarn by cooling air directed outward in the radial direction from the center, (8) JP-A-51-
Various methods have been proposed, such as placing a variable fluid in the passage of the spun traveling yarn below one spinneret surface as shown in No. 116,215. However, all of them have complicated structures, and it is difficult to observe the spinneret surface and the yarn immediately after spinning, and it is difficult to insert the cooling air blowing device. There are major operational problems, such as the equipment being obstructive and difficult to operate, and there are many deficiencies in actual operation.

In view of these circumstances, the present inventors used a spinneret with a large number of spinning holes (particularly 1000 or more holes) to
As a result of intensive research into an effective cooling method that does not require a separate cooling device and is easy to operate, the non-explosion pressure was reached. In other words, in order to spin a large number of spinning holes, particularly 1000 holes or more, through a spinneret hole arranged in a circular pattern, to uniformly cool a large number of yarns, and thereby obtain highly uniform synthetic fibers, it is necessary to At the same time, the accompanying airflow inside the running path of the yarn is discharged to the outside, and at the same time, the cooling air blown out from the cooling cylinder easily reaches the inside of the yarn, thus reducing the airflow inside the internal path of the running yarn. It is important to lower the temperature, and for this purpose, the n1ξ spinneret holes, which are basically arranged in a plurality of annular rows, are divided into two or more groups, or eight groups or more (preferably equally divided). I found something good. That is, the perforated annular row is provided with a non-perforated portion (non-perforated portion) extending from the outermost circumferential annular row to the innermost circumferential annular row, and the perforated annular row is divided into two or more groups by the non-perforated portion (non-perforated portion). I discovered that it can be divided into groups.

By dividing the perforation part of the spinneret into several perforation groups in this way, a passage is created between the inside and outside of the running yarn that allows airflow to enter and exit without being affected by the running yarn. As a result, the cooling air blown out from the cooling cylinder can easily reach the inside of the yarn, and the airflow temperature inside the passage can be lowered. Therefore, cooling of the inner yarn is not delayed compared to the outer side, and uniform cooling of the yarn becomes possible.

By the way, in such multi-hole spinning, a multi-hole spinneret is used in which the perforation part is divided into a plurality of groups, and each of the perforated spinning holes satisfies the following equations (1) and (2). It is essential and indispensable.

(1) 1.7≦P≦4 (2) 9≦400) 1/π(DI”-Dl”)≦35
However, P: interval between holes in the innermost circumferential row (■) Dl: outermost diameter of the hole array (w) Dl: innermost diameter of the hole array (■) H: number of holes (ke) In the present invention, the non-perforated portion is 9 or more. If the number of germination groups is 9 or more, not only will the airflow passage become so small that it loses its meaning as an airflow passage, but also turbulence of the airflow such as cooling air will occur, and as a result, the yarn will sway and the fused yarn will be damaged. 7) It is better to divide the perforation group into 2 or more groups and 8 groups or less, and it is more preferable to divide the perforation group into 3 to 5 groups.
That is to say.

In such a divided arrangement of perforation groups, the interval P(w) between the innermost holes in the same row with the minimum child interval is 11.7- or more, 4
-The following are preferred. With a diameter of 71- compared to 1.7-, the hole gap is too narrow and stable spinning is not possible, and there is no uniform cooling effect. On the other hand, if the size is larger than 4, the purpose of making the pores cannot be achieved, which is not preferable.

Furthermore, in the present invention, it is important to determine the number of holes H so as to satisfy the above formula (%) as a value corresponding to the perforation density of the spinning holes drilled in the plurality of annular tars.

If 400H/π(p, 2 p, 2-) is less than 9, the purpose of having the firstborn child will not be achieved and it is not desirable, and 35
If the amount is too large, satisfactory spinning will not be possible and the cooling effect will not be uniform.

Also, the ratio of the non-perforated part (non-perforated part) to the perforated part is the area of the perforated part 5t (c + 4) and the area of the non-perforated part (non-perforated part) 5
It is more preferable to provide the non-perforated portion (non-perforated portion) so as to satisfy the relationship 0.8≦81/St − )−Sz≦0.95 with respect to v(4). Here, if S1/S1+82 is smaller than 0.8, it is preferable from the point of view of cooling, but the area of the perforation portion occupying the area of the die is small and high productivity cannot be expected. On the contrary, Sl
If /S1+S2 is thicker than 0.95, high productivity cannot be expected, but uniform cooling cannot be obtained, and as a result, it becomes difficult to obtain uniform yarn. A more preferable range is 0.85≦Sl
/S1+8≦0.92.

The number of spinning holes arranged is preferably 8 or more rows in order to achieve high productivity and uniform cooling, but more than 20 rows is not preferred in terms of uniform cooling, and is preferably 8 to 20 rows.

The present invention will be explained below with reference to the drawings, but the drawings are just an example of the present invention, and the present invention is not limited thereto.

FIG. 1 is a schematic diagram of a spinning nozzle showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a cap body, in the center of which a hole 12 for mounting the cap is provided, and a pack 11.
When assembled into a breaker plate, etc., it is supported via a bottle. Reference numeral 2 indicates spinning holes drilled in the spindle, which are drilled on the array row 4 at a constant interval. In this figure, the number of arrays is shown as four columns for convenience, but as described above, the number of arrays may be any number as long as it is 8 to 20 columns. 3 indicates a non-perforated portion. This figure shows an example of a cap divided into four parts, and there are four non-perforated parts. Regarding the other items indicated by alphanumeric characters in Figure 1, DI is the outermost diameter of the hole array, D2 is the innermost diameter of the hole array, SL is the perforation area,
82 indicates the area of the partition portion.

FIG. 2 is a conceptual diagram showing a state in which spinning is performed using the spindle according to the present invention.

1 is a spinneret main body, and a spun thread 6 discharged from the spinneret hole
is cooled and solidified by the cooling air blown out from the cooling device 5. After that, the guide 7 collects the material, and the oil application device 8 applies the oil, and then the direction changing roller 9
It is picked up after changing the direction of travel through the . At this time, the yarn-free portion 10 produced by the non-perforated portion of the cap of the present invention serves as a passage for airflow. That is, the cooling air blown out from the cooling cylinder can easily reach the inside, and at the same time, the accompanying airflow, etc. inside the passage of the running yarn is blown out to the outside of the yarn through this passage. In this way, the airflow temperature in the internal passage of the running yarn is reduced, there is no delay in cooling the inner yarn, and uniform cooling becomes possible.

EXAMPLES In order to specifically explain the effects of the present invention, Examples will be shown below. The quality of the test results was comprehensively judged based on (1) the occurrence of yarn breakage during spinning, (2) the occurrence of fused yarn, and (S) the cross-sectional uniformity of the spun yarn after being taken off.

Evaluation was performed based on the following criteria.

(1) Spinning condition ○ mark - The number of yarn breaks is less than 1 time during 4 hours of spinning - △ mark -
The number of yarn breakage is 2 to 5 x mark - The number of yarn breakage is 6 or more (2) Occurrence of fused yarn Take microscopic cross-sectional photographs of four spun yarns at 50 m intervals,
Count the number of fused threads.

Mark 0 - The occurrence of fused threads is 0. △ Mark - The occurrence of fused threads is 2 to 4. × Mark - The occurrence of fused threads is 5 or more. The fluctuation rate given by the formula is 4% or more F△ mark - The above fluctuation rate is 4.1 inches to 7.5 inches
Take microscopic cross-sectional photographs of 5% or more spun fibers, take out 300 pieces arbitrarily, and measure the cross-sectional diameter d. The fluctuation rate X is X=σn/d
It is given by X100. Here, the average value 100 and standard deviation σn of the cross-sectional diameter are given by i.

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.64 measured at 30°C using a mixed solvent of equal weights of phenol and tetrachloroethane was spun into a spinneret having a spinning hole with a pore diameter of 0.2 tmφ. φ), the spinning temperature was 285° C., the take-off speed was 120 (117 minutes), and the discharge amount was adjusted so that the single fiber denier of the spun yarn after being taken-off was 4.0 denier.

was used.

In addition, the cooling device for spinning uses a cylindrical type,
The test was conducted with the cooling conditions fixed to the following conditions.

(1) Cooling air blowing position: Below the spinning gold 30
m(2) Inner diameter of cooling air outlet surface; 235+w(8
) Length of cooling air blowing surface: 250im (4) Temperature of cooling air: 25°C (6) Speed of cooling air: 0.75 m/sec Test results are shown in Table 1.

Further, the application of oil was carried out using an ordinary oiling roller.

Table 1] However, Sl: Area of perforated part (-) S2; Area of non-perforated part (-) i-S) 2 to 5-1 of A. However, it is within the scope of the present invention, and a good result was obtained (4+. On the other hand, Tess) 4
No. 1 had a no-split nozzle, and there were many fused threads and the cross-sectional uniformity was poor, so fluff and curling occurred frequently during the drawing process, making it impossible to obtain a normal product. There wasn't. “Test flat 6 was an example of division exceeding the upper limit of the present invention, and during spinning, fused yarns and single yarns frequently broke due to turbulence in the airflow, and satisfactory spinning could not be achieved.

Example 2 Polyethylene terephthalate having an intrinsic viscosity of 0.64 measured at 30°C using a mixed solvent of equal weights of phenol and tetrachloroethane was spun into a spinneret having a pore diameter of 0.25+w+φ (nozzle diameter 200-φ). ) at a spinning temperature of 290° C. and a take-off speed of 100θTn15), and the discharge amount was adjusted so that the single fiber denier of the spun yarn after being taken was 5.0 denier.

The spinneret used at this time had a hole arrangement of 15 rows, a pitch between the rows Ld 1.8 tea, and a hole gap in the innermost row of 1.94.
It is a cage, and the number of holes for the cap wire is 3150. This cap was filled with 2,730 holes using a tapered aluminum bottle, and then used for testing. Note that a cylindrical cooling device was used for spinning, and the trial run was conducted with the cooling diameter fixed to the following conditions.

(1) Cooling air blowing position: below the spinneret 30
m+(2,) Inner diameter of cooling air outlet surface; 235mm (
8) Length of cooling air blowing surface: 300 m (4) Temperature of cooling air: 25°C (5) Speed of cooling air: 1.2 m/sec The test results are shown in Table 2.

Further, the application of oil was carried out using an ordinary oiling roller.

Test) A of 48.9.10 was within the scope of the present invention, and good results were obtained. On the other hand, in the test of Flat 7 in which no IP perforations were provided, the fusion of the internal yarns was severe and it was impossible to achieve satisfactory spinning.

In addition, normal spinning was impossible for the test flat 11 which exceeded the upper limit of the division according to the present invention due to the turbulence of the air flow.

Table 2: Sl: Area of perforated area (-) S2: Area of non-perforated area (-) As shown in the examples, the present invention can maximize its effects particularly in multi-hole spinning, and These improvements have made it possible to uniformly cool porous spinning, and without the need for extra cooling or accessory equipment, it is possible to operate porous spinning with the same operability as conventional spinning processes. It is excellent in practical use.

[Brief explanation of the drawing]

FIG. 1 is a schematic view showing one embodiment of the melt spinning nozzle used in the present invention, and FIG. 2 is a schematic view showing one state when spinning using the spinneret according to the present invention. l: spinneret, 2: spinning hole, 3: non-perforated part (non-perforated part),
4; Arrangement row of spinning holes, 5; Cooling device, 6; Yarn, 7; Guide, 8; Oil supply device, 9; Direction changing roller, 10
；Mushi East Running Department, 11; Cap back, 12; Bolt hole for attaching the clasp Patent applicant RiRa Co., Ltd. Representative Patent Attorney Ken Honda

Claims (1)

[Scope of Claims] 1. In a melt spinner in which spinning holes are arranged in a plurality of annular rows, each of the perforated annular rows has a non-perforated portion (no holes) extending from the outermost annular row to the innermost annular row. The perforated annular row is divided into 2 groups or more and 8 groups or less from the non-perforated part (non-perforated part) K, and the perforated spinning holes meet the following formulas (1) and (2). A melt spinning spinneret characterized by satisfying the following. (1) 1.7≦P≦4 However, P: Interval between holes in the innermost row (depression) Dl: Outermost diameter of hole array (fi) D2: Innermost diameter of hole array (■) H: Number of holes (ke) 2. The area 51 (d) of the perforated part and the area 52 (c/A) of the non-perforated part (non-perforated part) are made so that the relationship 0.8≦81/81+82≦0.95 is satisfied. The melt spinning nozzle according to claim 1, further comprising a perforated portion (non-perforated portion). 3. The melt spinning nozzle according to claims 1 to 2, wherein the number of arranged spinning holes is 8 to 20.