JP3668004B2 - Melt spinning equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a melt spinning apparatus in which denier spots (fineness spots) and nonuniform cooling do not occur in melt spinning of thermoplastic synthetic fibers, and in particular, an ultrafine single fiber yarn comprising multifilaments having a single fiber fineness of 0.6 denier or less. The present invention relates to a melt spinning apparatus for melt spinning a strip.
[0002]
[Prior art]
In general, when melt spinning a fiber made of a thermoplastic synthetic resin such as polyester or nylon, the molten thermoplastic polymer is discharged from a spinneret, cooled by cooling air flowing in a direction crossing the spinning yarn group, and then drawn. And taking over is done.
[0003]
Such ultrafine fibers having a single fiber freshness of 0.6 denier or less obtained by melt spinning are used as materials for high value-added products such as artificial leather and high-quality clothing. The ultrafine fibers used for such applications have a single fiber fineness of at least 1.0 denier, and the fineness when a multifilament yarn is an aggregate of single fibers is 20 denier or more. Is required. Therefore, in order to produce such ultrafine fibers, it is essential to perform spinning using a multi-hole spinneret.
[0004]
However, such multi-hole spinning tends to cause uneven cooling in the process of cooling and solidifying the spun yarn. This non-uniformity of cooling causes variations in physical properties between the single fibers constituting the multifilament yarn, process troubles such as thread breakage, lengthwise fineness spots, dye spots, etc. in each single fiber. It was difficult to obtain ultra-fine multifilament yarn with sufficient quality. In particular, when cooling air is blown across the spun yarn, such a phenomenon occurs when the spun yarn swings under the influence of the cooling air.
[0005]
In recent years, the spinning speed has been increased for reasons such as improving the productivity. For this reason, the air flow accompanying the running spinning yarn has increased with an increase in the spinning speed. Increasingly, this accompanying air flow is a major cause of the yarn swinging of the spun yarn.
[0006]
In order to solve such problems, various studies have been made conventionally. For example, in Japanese Patent Laid-Open No. 4-18107, the arrangement of the polymer discharge holes formed in the spinneret is devised to eliminate the cooling difference between the cooling air blowing side and the anti-blowing side spinning yarn, It has been proposed to eliminate uneven cooling by improving the passage of cooling air so that the cooling air can easily pass between the spun yarns.
[0007]
However, in this method, since no consideration is given to the increase of the accompanying airflow due to the increase in the number of holes or the increase in speed and the occurrence of fineness spots caused by the yarn fluctuations induced thereby, in particular, 90 holes In the above-described multi-hole spinning and high-speed spinning at 2500 m / min or more, the above-mentioned yarn wobbling becomes remarkable.
[0008]
Accordingly, in Japanese Patent Publication Nos. 59-40923, 63-145407, etc., a current plate is provided along the running direction of the yarn group, or provided opposite to the cooling air blowing side. A method has been proposed in which outside air is sucked through a baffle plate, so that the cooling yarn is made uniform while the cooling air is disturbed and the fineness of the multifilament yarn is eliminated.
[0009]
However, even in this method, no consideration is given to the ease of passage between single fibers of yarn sway and cooling air induced by the increase in the accompanying airflow due to the increase in the number of holes and the increase in speed. It is not sufficient to reduce the occurrence of thread breakage and fineness spots. In addition, when trying to spin the above-mentioned ultrafine fibers at a high speed, the completion point of the thinning of the yarn shifts in the direction of the spinneret compared with the case of normal spinning, so the spun yarn is gradually cooled. The turbulence of the airflow in the slow cooling zone causes problems such as fineness spots as described above.
[0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and the problems to be solved by the present invention are as follows.
That is, when cooling air is blown to the yarn so as to cross the spun multifilament yarn and the melted multifilament yarn is cooled and solidified, fineness unevenness or non-uniformity mainly caused by yarn yarn swinging is produced. An object of the present invention is to provide a melt spinning apparatus capable of preventing uniform cooling.
[0011]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides the following means.
That is, “a multi-hole spinneret for spinning a thermoplastic synthetic fiber yarn composed of a large number of thermoplastic synthetic single fibers, a slow cooling zone for slowly cooling the spun yarn, the spun yarn Cooling air blocking member that blocks an inflow of cooling air from the lower part while leaving an opening for traveling, and a cooling device that cools the spun yarn by the cooling air blown across the spun yarn In this order,
A cylindrical spacer having a cylindrical traveling space in which the spun yarn travels, and a projection surface of the lower end opening of the traveling space in the yarn traveling direction substantially overlaps the opening of the cooling air blocking member; , A melt spinning apparatus provided close to the spun yarn in a slow cooling zone between the spinneret and the cooling air blocking member is provided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an example of an embodiment of the present invention, and a group of thermoplastic synthetic fiber yarns (multiple spindles in the embodiment shown in the figure) consisting of a large number of ultrafine single fibers having a single fiber fineness of 0.6 denier or less. It is the sectional side view which showed typically the melt spinning apparatus for ultra-fine fibers for spinning Y. FIG. 2 is a front sectional view thereof.
[0013]
In this figure, Y is a multifilament spun yarn, 1 is a spinning pack, 2 is a multi-hole spinneret, 3 is a cooling air blocking member, 4 is a cooling air supply chamber, and 5 is a cooling air pressure equalization. 6, an air supply rectification member, 6 ′ an intake rectification member, 7 a cylindrical spacer in which the spun yarn Y travels, 8 a yarn focusing guide that also serves as an oil application guide, and 9 Each cooling spinning cylinder is shown. In order to gradually cool the spun yarn Y, a slow cooling zone is provided between the spinneret 2 and the cooling air blocking member 3, but this slow cooling zone is not clearly shown in the present invention. It is surrounded by a heat insulating cylinder that is heated to maintain its internal atmosphere at a constant temperature.
[0014]
Here, the intake air rectifying member 6 ′ is provided opposite to the air supply rectifying member 6 with the spun yarn Y interposed therebetween, and intakes outside air rectified from the outside to the inside of the cooling spinning tube 9. Playing a role. The cooling air blocking member 3 blocks the flow of cooling air from below, leaving an opening for the spun yarn Y to travel so that the cooling air does not enter the slow cooling zone immediately below the spinneret 2. It is provided. In the embodiment of FIG. 1, the “cooling device” referred to in the present invention refers to the cooling air supply chamber 4, the cooling air pressure equalizing member 5, the supply air rectifying member 6, the intake rectifying member 6 ′, and the cooling spinning. An apparatus including the tube 9 is indicated.
[0015]
At this time, the pressure equalizing member 5 of the cooling air is preferably manufactured by a member such as a wire mesh filter or a breathable sintered metal that causes a pressure loss when the cooling air passes. Because of this, in the cooling air blowing section of the cooling air supply chamber 4, the distribution of the cooling air blowing pressure, the wind speed, the air volume, etc. is made into a profile corresponding to the spinning conditions such as spinning speed, spinning yarn brand, etc. This is because it can be controlled. The cooling air controlled to such a preferable profile is supplied in a direction crossing the spinning yarn Y in the cooling spinning tube 9 from the air supply rectifying member 6 that supplies the rectified cooling air.
[0016]
In the melt spinning apparatus configured as described above, the yarn Y spun from the multi-hole spinneret 2 attached to the spin pack 1 is brought to a predetermined value by the heat retaining cylinder 7 directly below the spinneret. It is led to the maintained slow cooling zone L ₁ . Subsequently, the air is guided to the cooling zone L ₂ that is cooled by the cooling device. In the cooling zone L ₂ , the cooling zone L ₂ is cooled and solidified by cooling air supplied in a direction crossing the spun yarn Y from the air supply rectifying member 6 made of a member having a rectifying action such as a honeycomb. Further, an oil agent is applied and converged by a yarn focusing guide 8 that also serves as an oil agent application guide, and the yarn is picked up after being entangled with the yarn.
[0017]
At this time, the cooling air supplied across the spun yarn Y flows downward together with the air flow accompanying the traveling yarn Y, and the dynamic pressure in the cooling spinning cylinder 9 increases due to the flow of the cooling air. On the contrary, the static pressure in the cooling spinning cylinder 9 decreases. For this reason, the outside air rectified through the intake rectifying member 6 ′ naturally flows into the cooling spinning cylinder 9, and the spun yarn Y is cooled also from this direction. It should be noted that the installation length of the intake air rectifying member 6 ′ may be set to a preferable condition as appropriate in accordance with the spinning condition. For example, in the melt spinning of polyester, the effective length is preferably 300 to 700 mm along the running direction of the spun yarn Y.
[0018]
Next, the spacer 7 which is one of the major features of the present invention will be described in detail below.
As described above, the cooling air blocking member 3 that blocks the flow of the cooling air from the lower part while leaving an opening for the spinning yarn Y to travel, the cooling air flows into the slow cooling zone as described above, and the ambient temperature is It is provided for the purpose of preventing disturbance. For this reason, the opening for running the spun yarn Y needs to be provided close to the spun yarn Y.
[0019]
However, in order to make the spun yarn Y run stably without coming into contact with the cooling air blocking member 3, there is a limit to the size of the opening close to the spun yarn Y. Moreover, in general, in the multi-spindle spinning apparatus with the series weight arrangement, the design is made such that the cooling air blowing speed on the upstream side of the cooling device is higher than that on the downstream side from the viewpoint of preventing the close contact between the single fibers and fineness unevenness. For this reason, a phenomenon that the cooling air flows into the slow cooling zone from the opening of the cooling air blocking member 3 inevitably occurs. For such a phenomenon, the single fiber denier is not critically affected by a fiber having a certain degree of largeness, but particularly in the case of an ultrafine single fiber having a single fiber fineness of 0.6 denier or less, it is greatly affected. Needless to say. Needless to say, in a multi-spindle melt spinning apparatus, it is easy to receive the interaction between the yarns of the adjacent spindles. Therefore, the present invention is more effective in a melt spinning apparatus that spins a multi-filament yarn group composed of a large number of ultrafine single fibers having a single fiber fineness of 0.6 denier or less.
[0020]
For this reason, simply providing the opening of the cooling air blocking member 3 close to the spun yarn Y cannot solve the above-mentioned problems. For this reason, the spun yarn as shown in FIG. 1 and FIG. It is necessary to provide a cylindrical spacer 7 in which the strip Y travels in the vicinity of the spun yarn. At this time, the cylindrical spacer 7 has a cylindrical traveling space in which the spun yarn Y travels, and the projection surface of the lower end opening of the traveling space in the yarn traveling direction is the cooling air blocking member 3. It is preferably formed so as to substantially overlap the opening.
[0021]
Here, when the spacer 7 is not provided in the slow cooling zone, the flow of the airflow is once suddenly narrowed at the opening of the cooling air blocking member 3, so that the airflow is suddenly contracted and disturbed at this portion. Arise. However, according to the embodiment of the present invention in which the spacer 7 as described above is provided, the traveling space of the slow cooling zone can be gradually narrowed along the direction in which the spun yarn Y travels, and a sudden contraction It can be avoided that the part appears. Therefore, the flow of the airflow in the slow cooling zone can be made smooth, the turbulence of the airflow in the slow cooling zone can be prevented, and the yarn swaying of the spun yarn Y can be suppressed.
[0022]
At this time, the spacer 7 of the present invention is preferably provided in a non-contact manner with a slight gap (approximately 0.2 mm to several mm) between the spinneret 2 and the cooling air blocking member 3. In this way, the spacer 7 is thermally insulated from the spinneret 2 and the cooling air blocking member 3, and the factor that the temperature of the spacer 7 is disturbed by the heat conduction from the spinning nozzle 2 and the cooling air blocking member 3 to the spacer 7. Can be reduced. And it becomes easy to maintain the atmospheric temperature of a slow cooling zone to a fixed value by this, and generation | occurrence | production of the quality spot by non-uniform heating can be prevented about each spun single fiber relation. In addition, by forming a gap between the spinneret 2 and the spacer 7, the heated airflow can flow into the running region of the yarn from this gap, and the flow of the airflow in the slow cooling zone can be made smoother. can do.
[0023]
Furthermore, in the spacer 7 of this invention, it is preferable to form a hollow part between heat retention pipe | tubes along the running direction of the spun yarn of a slow cooling zone. By configuring the spacer 7 in this manner, the atmosphere of the hollow portion can be heated, and the spacer 7 can be controlled to a constant temperature by newly introducing a heated gas into the heated atmosphere or the hollow portion.
[0024]
Moreover, in the spacer 7 of this invention, it is preferable to provide a wrinkle at both ends where the spun yarn Y enters and exits. By doing so, it is possible to increase the inflow resistance of the airflow when the cooling air enters the hollow portion from the gap between the spacer 7 and the cooling air blocking member 3.
[0025]
【The invention's effect】
According to the present invention described above, the cooling air is blown to the yarn so as to cross the spun multifilament yarn, and when the melted multifilament yarn is cooled and solidified, it is mainly caused by yarn swing. To prevent fineness spots and uneven cooling. In this case, particularly in a melt spinning apparatus for spinning a multi-thread group consisting of a large number of ultrafine single fibers having a single fiber fineness of 0.6 denier or less, a greater effect can be obtained.
[0026]
As described above, according to the present invention, it is possible to eliminate the occurrence of yarn fluctuation due to non-uniform cooling and turbulence of cooling air. There is an extremely great effect that a multifilament yarn composed of a large number of ultrafine single fibers having a fiber fineness of 0.6 denier or less can be obtained by multi-spinning.
[Brief description of the drawings]
FIG. 1 is a side sectional view schematically illustrating a melt spinning apparatus of the present invention.
FIG. 2 is a front sectional view schematically illustrating the melt spinning apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Spin pack 2 Spinneret 3 Cooling air blocking member 4 Cooling air supply chamber 5 Cooling air pressure equalizing member 6 Supply air rectifying member 6 'Intake rectifying member 7 Spacer Y Spinning yarn

Claims (6)

A multi-hole spinneret for spinning a yarn composed of a large number of thermoplastic synthetic single fibers, a slow cooling zone for slowly cooling the spun yarn, and an opening for running the spun yarn remain. A cooling air blocking member that blocks inflow of cooling air from the lower part, and a cooling device that cools the spun yarn by cooling air blown across the spun yarn, in this order,
A cylindrical spacer having a traveling space in which a lower end opening surface of the traveling space in which the spun yarn travels substantially overlaps the opening of the cooling air blocking member is formed between the spinning nozzle and the cooling air blocking member. A melt spinning apparatus attached to the slow cooling zone in proximity to the spun yarn. The melt spinning apparatus according to claim 1, wherein the spacer is provided in a non-contact manner with a slight gap between the spinneret and the cooling air blocking member. The melt spinning apparatus according to claim 1 or 2, wherein a hollow portion is formed in the slow cooling zone along a running direction of the spun yarn by a cylindrical spacer. The melt spinning apparatus according to any one of claims 1 to 3, wherein ridges are provided at both ends of the cylindrical spacer. The melt according to any one of claims 1 to 4, which is a melt spinning apparatus for ultrafine fibers for spinning thermoplastic synthetic fiber yarns composed of a large number of ultrafine single fibers having a single fiber fineness of 0.6 denier or less. Spinning device. The melt spinning apparatus according to any one of claims 1 to 5, wherein the melt spinning apparatus is a spinning apparatus for spinning a multi-yarn yarn group.

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