JP2838042B2 - Porous spinneret and method for melt-spinning ultrafine multifilament yarn using this spinneret - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spinneret used for melt-spinning ultrafine multifilament yarns having a single-fiber fineness of 1 denier or less and 200 filaments or more using a thermoplastic polymer such as polyester or polyamide. And a method for melt-spinning an ultra-fine multifilament yarn using the spinneret.

[0002]

2. Description of the Related Art In recent years, synthetic fiber yarns such as polyester and polyamide have been developed in view of the feeling and functionality of the resulting fabric.
What has a small single yarn fineness is required. In order to efficiently produce a multifilament yarn with such fine denier, melt spinning is performed using a spinneret having a large number of spinning holes formed in one spinneret.

Japanese Patent Application Laid-Open No. 55-112 discloses a spinneret for melt-spinning an ultra-fine multifilament yarn having a single yarn fineness of 1 denier or less.
Japanese Patent Publication No. 305 proposes a melt spinneret capable of extremely reducing uneven spots between single yarns when cooling using an annular cooling device provided downstream. This spinneret is
An equal number of spinning holes are arranged on a plurality of concentric circles and on a plurality of radiations having the same central angle.

This spinneret does not take into account the relationship between the distance from the cooling air blowing surface of the annular cooling device to the spinning hole, and therefore the outermost periphery of the spinneret perforated from the cooling air blowing surface of the annular cooling device. When the distance to the spinning holes in the row is small, the single yarn in the outermost row is blown by cooling air having a high blowing speed, causing close contact with the single yarn in the inner circumferential row, and the spinnability is extremely poor. Conversely, if the distance from the cooling air blowing surface of the annular cooling device to the outermost row of spinning holes drilled in the spinneret is large, the cooling air does not reach the innermost row of yarn sufficiently, Insufficient cooling of the single yarns in the row causes single yarn breakage.

[0005] Even if the distance from the cooling air blowing surface of the annular cooling device to the outermost row of spinning holes perforated in the spinneret is appropriate, the single yarn fineness can be reduced to 1 using this spinneret. When a yarn having a denier of 200 filaments or less is melt-spun, the cooling of the yarn becomes insufficient, and adhesion between single yarns and yarn breakage frequently occur.

That is, in order to arrange more than 200 spinning holes in this spinneret, there is a case where an interval between the spinning holes on a concentric circle is ensured, and a case where an interval between the spinning holes on a radiation line is ensured. May be caused. First, in the case of a spinneret that secures the interval between the spinning holes on the concentric circles, the number of holes on each ray may be increased to reduce the number of holes on each concentric circle. Does not reach sufficiently, the cooling becomes insufficient, and the yarn near the inner circumferential row is in close contact between the single yarns, and the yarn is likely to break.

In order to secure the spacing between the spinning holes on the radiation, the number of holes on each radiation may be reduced by increasing the number of holes on the concentric circles. The yarn on each concentric circle acts like a screen against the cooling air to be blown, and it becomes difficult to introduce cooling air to the inner circumferential yarn. Cutting occurs.

Therefore, when the melt spinning is performed using the spinneret as described above, the cooling air is not introduced to the yarns in the vicinity of the inner circumferential row, so that the cooling becomes insufficient and the adhesion between the single yarns and the single yarn breakage occur frequently. , The obtained yarn is apt to stain, etc.
There was a problem that the uniformity was poor.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and melts and spins a fine multifilament yarn of 200 filaments or more having a single yarn fineness of 1 denier or less with good spinning condition. A perforated spinneret capable of uniformly cooling with an annular cooling device and producing a yarn with excellent uniformity without causing close contact or breakage of a single yarn, and melt spinning of an ultrafine multifilament yarn using this spinneret. It is a technical task to provide a method.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and have found that the arrangement of the spinning holes of the spinneret is at a distance from the inner peripheral surface of the cooling air blowing surface of the annular cooling device. Block B ₁ for selecting the appropriate and spinning holes
And the block B ₂ which is not pierced are provided alternately.
_By making a spinneret that regulates the hole density to be bored in ₁ , and by appropriately selecting the cooling conditions of the annular cooling device,
It has been found that the yarn spun from the spinneret can be uniformly cooled, and a yarn with excellent uniformity can be obtained, and the present invention has been achieved.

That is, the gist of the present invention is as follows. [A] A spinneret used for multifilament melt spinning in which a spun yarn is cooled by an annular cooling device provided downstream of the spinneret holder, wherein the total number of spinning holes perforated in the spinneret is 200.
As described above, the arrangement of these spinning holes is as follows (1) to
A perforated spinneret which simultaneously satisfies the requirement of (4). (1) relative to the inside diameter D ₀ of the cooling air blowout face of the annular cooling device, the diameter D ₂ between the diameter D ₁ of the outermost row of the innermost row has been spinning holes drilled on multiple concentric circles in the formula ranges Being within. 0.5 ≦ D ₁ / D ₀ ≦ 0.7 0.4 ≦ D ₂ / D ₀ ≦ 0.6 (2) The die surface is divided into a plurality of blocks by radiation having the origin at the die center point, and the spinning hole Block B ₁ with holes
And blocks B _{2 which} are not perforated are provided alternately in a ring,
The number must be within the range of the following formula. 6 ≦ B ₁ = the ratio of B ₂ ≦ 16 (3) central angle of the center angle α and the block B ₂ block B ₁ beta is in the range of the following formula. 0.8 ≦ β / α ≦ 1.25 ( 4) spinning holes drilled in the blocks B ₁ represents, on a plurality of concentric circles the die center point as the origin, and, on a plurality of radiation a central angle equal And the pore density ρ (pieces /
cm ² ) is within the range of the following formula. 10 ≤ ρ ≤ 35 [B] The yarn spun from the spinneret is cooled by an annular cooling device provided downstream of the spinneret holder to obtain a multifilament yarn having a single yarn fineness of 1 denier or less. In a spinning method, a melt spinning method using the spinneret described in [A] and cooling under the following conditions (1) to (3). (1) The distance h from the lower surface of the spinneret holder to the annular cooling device is set to 20 to 100 mm. (2) Set the length l of the cooling air blowing surface of the annular cooling device to 100
~ 300 mm. (3) The cooling air blowing speed of the annular cooling device is 0.1 to 1.
5 m / sec.

Hereinafter, the present invention will be described in detail. FIG. 1 is a partial schematic view showing one embodiment of the perforated spinneret of the present invention, and FIG. 2 is a schematic process diagram showing one embodiment of a melt spinning step. First, the porous spinneret of the present invention will be described with reference to FIG. In the partial schematic diagram of FIG. 1, the cooling air is blown from the cylindrical filter 10 inside the annular cooling device toward the center point P of the spinneret 2. And the inner diameter D ₀ of the cylindrical filter 10 is a cooling air blowout face of the annular cooling device, the diameter D ₁ and the innermost row of the outermost rows of spinning holes H on the plurality of concentric circles that are drilled in the spinneret 2 it is necessary to make the ratio between the diameter D ₂ in the formula ranges. _{D 1 / D 0 = 0.5~0.7 D} 2 / D 0 = 0.4~0.6

When D ₁ / D ₀ exceeds 0.7, the spun yarn becomes close to the surface from which the cooling air is blown out, and the single yarns in the outer peripheral row are flowed by the cooling air, and the single yarns in the inner peripheral row And the spinnability is extremely deteriorated. On the other hand, if D ₁ / D ₀ is less than 0.5, the spun yarn is far from the blowing surface of the cooling air, so that the cooling air is hardly introduced between the single yarns, and Insufficient cooling causes breakage of single yarn.

On the other hand, if D ₂ / D ₀ exceeds 0.6, the range of perforating the spinning holes on the surface of the spinneret becomes small, so that the number of spinning holes is limited and the hole interval between the perforated spinning holes becomes small. The spun yarn adheres between the single yarns. on the other hand,
When D ₂ / D ₀ is less than 0.4, it is difficult for cooling air to be introduced to the innermost yarn, and the yarn is not sufficiently cooled.

Next, the area defined by the concentric circles of the diameters D ₁ and D ₂ of the spinneret surface is divided into a plurality of blocks by radiation having the origin at the center point of the spinneret. ₁ block B ₂ which are not perforated and are provided alternately in annular, it is necessary that the number is respectively 6 to 16. Thus, by partitioning the block B ₂ which is not perforated and the block B ₁ which is drilled spinning holes, the cooling air is introduced fully through the block B ₂ to the yarn of the innermost rows of blocks B ₁ In addition, uniform cooling of the yarn becomes possible.

When the number of B ₁ (or B ₂ ) is less than 6,
Since the number of spinning holes to be drilled in the block B ₁ is increased, less likely to be introduced cooling air to the yarn of the innermost rows of blocks B _1, a yarn cooler becomes insufficient. B ₁ (or B ₂ )
If the number of more than 16, since the angle of per block decreases, the cooling air is less likely to be introduced from the block B _2, the yarn cooler becomes insufficient.

Furthermore, the size of the central angle α of the block B ₁ represents, is required to be 0.8 to 1.25 times the central angle magnitude of β of B _2. Central angle magnitude of β of B ₂ is closely related to the spinning hole number, when the number of holes 144 relatively small as shown below, alpha to be cooled sufficiently by about 0.3 times However, if the number of holes is as large as 200 or more, the number of concentric circles increases, so the ratio of β to α is increased, and if the cooling air is not introduced, the cooling of the yarn in the inner peripheral part is insufficient. Become. Accordingly, the central angle magnitude of α in block B ₁ is greater than 1.25 times the size of the central angle β of B _2, the cooling air is no longer introduced to the yarn of the innermost rows of blocks B _1, Insufficient cooling of the yarn. When the center angle magnitude of α in block B ₁ is less than 0.8 times the size of the central angle β of B _2, the hole spacing of the spinning holes drilled in the block B ₁ is reduced, it is spun The warp yarn adheres between the single yarns.

The density ρ of the spinning holes drilled in the block B ₁
Should be 10 to 35 particles / cm ² . Pore density 10 /
If it is less than cm ² , cooling air is likely to be introduced, but the temperature around each single yarn is significantly reduced, and the spinning tension becomes excessive due to the accompanying airflow generated with cooling, resulting in extremely poor spinnability. This indicates that it is effective to collect a plurality of single yarns as the single yarn denier becomes smaller and to prevent the temperature around each single yarn from extremely dropping. ^If it exceeds ² , undesired adhesion may occur between the single yarns depending on the thickness of the single yarns.

The shape of the spinning hole to be formed in the spinneret is not particularly limited, and may be any one of a round cross section, a three-leaf, a six-leaf or other irregular cross-section.

Next, the method for melt-spinning an ultrafine multifilament yarn of the present invention will be described with reference to FIG. The melted thermoplastic polymer is spun from a spinneret 2 attached to a spinneret holder 1, and the yarn Y is passed through a hood 3 provided downstream of the spinneret holder 1, After being cooled and solidified by the air blown out from the cylindrical filter 10 inside the provided annular cooling device 4, the oil agent is applied by the oil agent applying device 5, the yarn is further bundled by the yarn path guide 6, and then taken off. It is wound by a winder 9 via rollers 7 and 8.

In this case, the distance h from the lower surface of the spinneret holder to the annular cooling device needs to be 20 to 100 mm, and the distance h depends on the size of the single yarn fineness and the number of filaments.
Is adjusted within this range. When the distance h exceeds 100 mm,
With an ultrafine yarn of 1 denier or less, the cooling point of the yarn is shifted, resulting in a yarn with poor uniformity. If the distance h is less than 20 mm, the distance from the lower surface of the spinneret to the annular cooling device is short, and the spinneret is cooled by the cooling air, so that yarn breakage or the like occurs during spinning, and the spinnability deteriorates. Note that the distance h to the annular cooling device usually indicates the length of the hood portion 3 as shown in FIG.

The length l of the cooling air blowing surface of the annular cooling device must be 100 to 300 mm. The length l is adjusted within this range according to the size of the single yarn fineness and the number of filaments. If the length 1 is less than 100 mm, the cooling of the yarn becomes insufficient, uniform cooling is not possible, and the yarn has cooling unevenness. If the length 1 exceeds 300 mm, the accompanying airflow of the traveling yarn increases, and the yarn tension increases, thereby deteriorating the spinnability.

Further, the blowing speed of the cooling air from the annular cooling device needs to be 0.1 to 1.5 m / sec. When the blowing speed of the cooling air exceeds 1.5 m / sec, the single yarn in the outermost row of the spinneret is blown off, and the adjacent single yarns adhere to each other,
Thread breaks occur. If the blowing speed of the cooling air is less than 0.1 m / sec, it becomes substantially difficult to cool the yarn. In addition,
The blowing speed of the cooling air refers to the wind speed at the cooling air blowing surface of the annular cooling device.

As the thermoplastic polymer which can be spun by using the spinneret of the present invention, polyester or nylon 6, 66 having ethylene terephthalate as a main repeating unit is preferably used. Or a modified polymer obtained by copolymerizing the third component.

[0025]

Next, the present invention will be described specifically with reference to examples. In addition, the physical property value and evaluation in an Example were performed as follows. (1) Spinning condition The state at the time of winding the melt-spun yarn was evaluated in the following two stages.良好 Good spinning without breakage for 5 hours or more. × The thread breaks within a few minutes after the thread is wound on the winder, or the winder cannot be wound at all. (2) Yarn uniformity The thickness of the wound yarn was measured by a half inert test using a Worcester tester manufactured by Zellbeger Worcester Co., Ltd., and evaluated by the following two steps. ○ Thickness unevenness less than 3% × Thickness unevenness 3% or more (3) Dyed spot The obtained yarn is false-twisted by a low-speed pin false twisting machine, and the obtained processed yarn is knitted in a tubular manner, and then subjected to a conventional method. Stained. Subsequently, the dyed spots on the obtained dyed tubular knitted fabric were visually checked, and evaluated in the following three stages. ○ No spots. Δ: There is partial color difference, but commercialization is possible. × Nearly all samples show clear color differences,
It cannot be commercialized. (4) Overall evaluation ○ Both spinning condition and quality are good. C: There is a defect in any of spinning condition and quality, and it is defective.

Example 1 Intrinsic viscosity (measured at 20 ° C. using an equal weight mixture of phenol and ethane tetrachloride as a solvent) A polyethylene terephthalate chip of 0.68 was melted at a temperature of 290 ° C. and a spinning temperature of 29 ° C.
The fiber was spun from a spinneret having a hole diameter of 0.15 mm at a discharge rate of 51.2 g / min at 8 ° C. A hood portion having a length of 30 mm is provided on the lower surface of the spinneret holder, a distance h from the lower surface of the spinneret holder to the annular cooling device is 30 mm, and a cylindrical filter having a cooling air blowing surface length l of 200 mm is provided downstream thereof. The provided annular cooling device was installed, and cooling air at a speed of 0.5 m / sec was blown from the cylindrical filter to cool the spun yarn. At this time, the diameter D ₀ of the inner peripheral surface of the cylindrical filter which is the cooling air blowing surface is 11
4 mm, the number of drilled spinning holes on the spinneret face is 300 holes, the diameter D ₁ of the outermost rows of spinning holes is 72 mm, a diameter D ₂ of the innermost row 52 mm, on five concentric circles are arranged, the block B ₂ to the spinning hole is not drilled block B ₁ which is perforated provided 16, the center angle of the central angle α and the block B ₂ block B ₁ represents a 12 degrees, the blocks B ₁ Has a hole density ρ of 30.8 / cm ² . (This spinneret is a type.) An undrawn yarn of 148 denier / 300 filaments at a speed of 3200 m / min while bundling the yarn with a yarn path guide while applying a spinning oil to the cooled yarn. The strip was wound on a winder. Table 1 shows the spinning condition and the quality evaluation and overall evaluation of the obtained yarn at this time.

Examples 2 to 3 and Comparative Examples 1 to 3 The same procedure as in Example 1 was carried out except that the number of spinning holes and the arrangement of the spinning holes were variously changed as shown in Table 1.
Table 1 shows the spinning condition and the quality evaluation and overall evaluation of the obtained yarn at this time.

[0028]

[Table 1]

As is evident from Table 1, in Examples 1 to 3, the yarn can be spun satisfactorily without yarn breakage, and the obtained yarn is excellent in uniformity, and stains occur even when dyed. It was a good quality yarn without any. On the other hand, the value of D ₁ / D _{0 in} the equation is
In Comparative Example 1 exceeding 0.7 and Comparative Example 2 in which the value of β / α in the formula was less than 0.8, the cohesion between the single yarns of the spun yarn frequently occurred, yarn breakage occurred during spinning, and the spinning condition was increased. Was bad. Further, the obtained yarn was poor in uniformity, and when dyed, spots occurred, and both the operability and the quality were poor. Further, in Comparative Example 3 in which the value of β / α in the formula is 3.50, the cooling air is not introduced to the yarn in the innermost circumferential row, and the cooling of the yarn becomes insufficient.
The spinning condition was also poor and could not be taken up.

Examples 4-5, Comparative Examples 4-6 Distance h from the lower surface of the spinneret holder to the annular cooling device.
(Length of the hood) and the blowing speed of the cooling air were variously changed as shown in Table 2, and the same procedure as in Example 1 was performed. Table 2 shows the spinning condition at this time and the evaluation of the quality of the obtained yarn and the overall evaluation.

[0031]

[Table 2]

As is clear from Table 2, in Examples 4 and 5, the yarn can be spun satisfactorily without yarn breakage, and the obtained yarn is excellent in uniformity, and even when dyed, spots are generated. It was a good quality yarn without any. The blowing speed of cooling air is 1.5 m
In Comparative Example 4 in which the speed exceeded / second, the single yarn in the outermost row of the spinneret was blown off, and yarn breakage occurred, resulting in poor spinning condition. In Comparative Examples 5 and 6 in which the distance h was more than 100 mm, adhesion between the single yarns occurred, the yarns were broken, uniform cooling was not possible, and the yarns were uneven with cooling unevenness. Was.

Examples 6 to 7 and Comparative Examples 7 to 10 Distance h from the lower surface of the spinneret holder to the annular cooling device.
(The length of the hood) is 30 mm, the diameter D ₀ of the inner peripheral surface of the cylindrical filter is 140 mm, and the length l of the cooling air blowing surface is l.
The procedure was performed in the same manner as in Example 1 except that the cooling air blowing speed, the number of spinning holes perforated in the spinneret, and the arrangement of the spinning holes were variously changed as shown in Table 3. Table 3 shows the spinning condition and the evaluation of the quality of the obtained yarn and the overall evaluation at this time.

[0034]

[Table 3]

As is clear from Table 3, in Examples 6 and 7, the yarn can be spun satisfactorily without yarn breakage, and the obtained yarn is excellent in uniformity, and even when dyed, spots are generated. It was a good quality yarn without any. In Comparative Example 7 in which the value of D ₂ / D ₀ was less than 0.4, cooling air was not introduced to the innermost yarn, cooling of the yarn was insufficient, and adhesion between single yarns and yarn breakage And the spinning condition was poor. In addition, the obtained yarn had cooling spots, and when dyed, spots occurred, resulting in poor quality. In Comparative Example 8 in which the length 1 exceeded 300 mm, the uniformity of the obtained yarn was excellent, but the spinning tension was increased due to the accompanying airflow, yarn breakage occurred, and the spinning condition was poor. In Comparative Example 9 in which the blowing speed of the cooling air was 1.6 m / sec, the single yarn in the outermost row of the spinneret was blown off, the adhesion between the single yarns was large, the yarn was broken, and the spinning condition was increased. Was bad. Comparative example in which the blowing speed of the cooling air was 2.0 m / sec
In No. 10, more yarn breakage occurred than in Comparative Example 9, and the yarn could not be wound.

[0036]

According to the present invention, since the yarns can be cooled uniformly without causing adhesion between the single yarns and yarn breakage, high quality single yarns having excellent uniformity and no occurrence of spots are obtained. Fineness is 1
It becomes possible to produce ultra-fine multifilament yarns having a denier of 200 filaments or less with good operability.

[Brief description of the drawings]

FIG. 1 is a partial schematic view showing one embodiment of a perforated spinneret of the present invention.

FIG. 2 is a schematic process chart showing one embodiment of a melt spinning step of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spinneret holder 2 Spinneret 3 Hood part 4 Annular cooling device 5 Oil supply device 6 Yarn guide 7, 8 Take-off roller 9 Winder 10 Cylindrical filter H Spinning hole P Center point

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-107005 (JP, A) JP-A-55-112305 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) D01D 4/02

Claims (2)

(57) [Claims] 1. A spinneret used for multifilament melt spinning in which a spun yarn is cooled by an annular cooling device provided downstream of a spinneret holder, wherein the total number of spinning holes perforated in the spinneret is 1. 200 or more, wherein the arrangement of the spinning holes simultaneously satisfies the following requirements (1) to (4). (1) relative to the inside diameter D ₀ of the cooling air blowout face of the annular cooling device, the diameter D ₂ between the diameter D ₁ of the outermost row of the innermost row has been spinning holes drilled on multiple concentric circles in the formula ranges Being within. 0.5 ≦ D ₁ / D ₀ ≦ 0.7 0.4 ≦ D ₂ / D ₀ ≦ 0.6 (2) The die surface is divided into a plurality of blocks by radiation having the origin at the die center point, and the spinning hole Block B ₁ with holes
And blocks B _{2 which} are not perforated are provided alternately in a ring,
The number must be within the range of the following formula. 6 ≦ B ₁ = the ratio of B ₂ ≦ 16 (3) central angle of the center angle α and the block B ₂ block B ₁ beta is in the range of the following formula. 0.8 ≦ β / α ≦ 1.25 ( 4) spinning holes drilled in the blocks B ₁ represents, on a plurality of concentric circles the die center point as the origin, and, on a plurality of radiation a central angle equal And the pore density ρ (pieces /
cm ² ) is within the range of the following formula. 10 ≦ ρ ≦ 35 2. A multi-filament melt-spinning method for cooling a yarn spun from a spinneret by an annular cooling device provided downstream of the spinneret holder to obtain a yarn having a single yarn fineness of 1 denier or less. A melt spinning method using the spinneret according to claim 1, and cooling under the following conditions (1) to (3). (1) The distance h from the lower surface of the spinneret holder to the annular cooling device is set to 20 to 100 mm. (2) Set the length l of the cooling air blowing surface of the annular cooling device to 100
~ 300 mm. (3) The cooling air blowing speed of the annular cooling device is 0.1 to 1.
5 m / sec.