JP2007224446A - Melt spinning apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a melt spinning apparatus and method with which a yarn having excellent uniformity ratio of illuminance is obtained. <P>SOLUTION: A melt spinning apparatus having a spinneret with annularly arranged spinning holes and a cooling cylinder with a cooling air blowing part 8 equipped with a plurality of air blasting holes arranged inside a resin spun from the annularly arranged spinning holes below the spinneret is used, cooling air is blown out from the cooling cylinder so as to make the air velocity distribution of the cooling air at the cooling air blowing part satisfy relational expression represented by formula V<SB>jmax</SB>≤25.0 (m/sec) ¾V<SB>a</SB>-V<SB>j</SB>¾<0.14×V<SB>a</SB>(V<SB>j</SB>is an air velocity V<SB>jmax</SB>at an arbitrary part in a range of ≥5% and <70% of the whole length of the cooling air blowing part from the highest part in a resin traveling direction of the cooling air blowing part; V<SB>jmax</SB>is the maximum of V<SB>j</SB>and V<SB>a</SB>is an average air velocity at a part in a range of ≥5% and <70% of the whole length of the cooling air blowing part from the highest part in the resin traveling direction of the cooling air blowing part) and a melt spun resin is solidified. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a melt spinning apparatus having a cooling cylinder that is provided at a lower center portion of a spinneret and supplies cooling air, and a melt spinning method using the same, and more specifically, a single yarn fineness having excellent uniformity. The present invention relates to a melt spinning apparatus that can be suitably used for obtaining an ultrafine multifilament of 1.5 dtex or less (hereinafter referred to as ultrafine yarn) and a melt spinning method using the melt spinning apparatus.

  A melt spinning apparatus provided with a cooling cylinder for supplying cooling air to the central portion below the spinneret is introduced in, for example, Patent Document 1. However, in the apparatus described in this document, there is a problem that a fast cooling air hits an unsolidified polymer immediately after spinning, and yarn swinging is likely to occur, rather the yarn uniformity is easily deteriorated. In particular, when spinning a very fine yarn having a large specific surface area and having a single yarn fineness of 1.5 dtex or less, the yarn sway is increased, and fineness of the yarn is generated.

Patent Documents 2 and 3 disclose a method of controlling the velocity distribution in the longitudinal direction of the cooling cylinder of the cooling air discharged from the cooling cylinder. However, each of the methods described in these documents has a problem that the cooling air speed is reduced or increased in the longitudinal direction of the cooling cylinder, so that the cooling air is likely to be excessive or insufficient, and it is difficult to stably cool the yarn. As a result, it is difficult to obtain a yarn with excellent uniformity.
Japanese Patent Laid-Open No. 52-15615 JP 61-174411 A JP 63-219612 JP

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a melt spinning apparatus and a melt spinning method capable of producing a yarn having excellent uniformity.

In order to achieve the above object, the present invention has the following configuration. That is,
(1) A spinneret in which the spinning holes are arranged annularly, and a cooling cylinder arranged below the spinneret and inside the thermoplastic resin spun from the annularly arranged spinning holes. In the melt spinning apparatus, the cooling cylinder has a cooling air blowing portion having a plurality of blowing holes, and the air velocity distribution of the cooling air in the cooling air blowing portion satisfies the following relational expression. A melt spinning apparatus characterized by that.

V _jmax ≦ 25.0 (m / sec)
│V _a -V _j │ <0.14 × V _a
However,
V _j is the wind speed at any part in the range of 5% or more and less than 70% of the total length of the cooling air blowing part from the uppermost end of the cooling air blowing part in the resin running direction
V _jmax is the maximum value of V _j
V _a is the average wind speed in the range of 5% or more and less than 70% of the total length of the cooling air blowing part from the uppermost end of the cooling air blowing part in the resin running direction. The melt spinning apparatus according to (1), wherein the melt spinning apparatus includes a porous member provided on an upstream side of the air blowing hole with respect to the flow direction and over the entire direction intersecting the cooling air flow direction.
(3) A spinneret in which the spinning holes are arranged annularly, and a plurality of blower holes arranged below the spinneret and inside the resin spun from the annularly arranged spinning holes. Using a melt spinning apparatus equipped with a cooling cylinder having a cooling air blowing portion and blowing the cooling air from the cooling cylinder so that the wind speed distribution of the cooling air in the cooling air blowing portion satisfies the following relational expression, and melt spinning: A melt spinning method characterized by solidifying the obtained resin.

V _jmax ≦ 25.0 (m / sec)
│V _a -V _j │ <0.14 × V _a
However,
V _j is the wind speed at any part in the range of 5% or more and less than 70% of the total length of the cooling air blowing part from the uppermost end of the cooling air blowing part in the resin running direction
V _jmax is the maximum value of V _j
V _a is the average wind speed in the range of 5% to less than 70% of the total length of the cooling air blowing part from the uppermost end in the resin running direction of the cooling air blowing part. Here, “cooling air blowing part” means the spinneret The part where the ventilation hole is provided in the most downstream location of the cooling cylinder which supplies the cooling air to the thermoplastic resin discharged from is said.

  In addition, a plurality of spinning holes are provided in an “annular” manner, in which a plurality of spinning holes are provided to such an extent that a gap is formed inside the plurality of discharged filaments so that a cooling cylinder can be disposed. State.

According to the present invention, the wind speed distribution in the cooling air blowing portion of the cooling air blown from the cooling cylinder is a constant relational expression in the resin running direction,
V _jmax ≦ 25.0 (m / sec)
│V _a -V _j │ <0.14 × V _a
However,
V _j is the wind speed at any part in the range of 5% or more and less than 70% of the total length of the cooling air blowing part from the uppermost end of the cooling air blowing part in the resin running direction
V _jmax is the maximum value of V _j
V _a because meet average wind speed at the portion in the range of 5% to less than 70% of the cooling air blow BBW entire length from the resin running direction uppermost end of the cooling air blow chubby, resin discharged from the spinning holes, the It is cooled and solidified under an atmosphere. In other words, in the upstream region where the resin discharged from the spinneret is not solidified, the cooling air is blown to such an extent that the resin is not shaken vigorously, and in the downstream region from when the resin starts to solidify until it is sufficiently cooled. By blowing cooling air having a wind speed within a certain range, uniform cooling is performed in the resin running direction, and as a result, a yarn having excellent uniformity can be obtained. Furthermore, when a fabric is produced using the yarn produced by the melt spinning apparatus or melt spinning method of the present invention, a high-quality fabric with less weaving, knitting steps, dyeing spots, etc. can be obtained.

  FIG. 1 is a schematic longitudinal sectional view showing an example of an apparatus according to the present invention, and FIG. 2 is a schematic view of the apparatus shown in FIG. This apparatus includes a spinneret 2 fixed by a pack housing 1 and a plurality of filaments discharged from a plurality of spinning holes 3 formed in an annular shape in the spinneret 2 below the spinneret 2. 4 has an inner diameter D that is larger than the maximum hole diameter d of the cooling cylinder 5 and the plurality of spinning holes 3 that are formed in an annular shape, that is, outside the filament 4. And the cooling cylinder 5 and the oil supply guide 7 arranged on the downstream side of the outer cylinder 6 and a winding means (not shown) of the solidified filament. A plurality of filaments 4 discharged from the spinning hole 3 are unsolidified resin immediately below the spinneret 2, cooled and solidified between the cooling cylinder 5 and the outer cylinder 6, and then supplied with oil. Is stretched and wound up.

  Here, the cooling cylinder has a hollow structure as shown in the schematic longitudinal cross-sectional view of FIG. 3. For example, the cooling cylinder is configured by sandwiching and fixing the cylinder that becomes the cooling air blowing portion 8 between the upper lid 9 and the base 10. The cylinder which becomes the cooling air blowing part 8 is composed of a porous member having a large number of capillary holes (air blowing holes) in the thickness direction, and the cooling air sent into the cooling cylinder is threaded from the cooling air blowing part. The resin is blown out while being rectified in the strip direction to cool the resin. As a porous member, it should just have moderate rigidity, and paper, wood, a metal, a synthetic resin, etc. can be used. For example, a cellulose ribbon may be wound in a spiral shape, impregnated with a thermosetting resin such as a phenol resin, and heat-cured to form holes having a size of about 40 μm over the entire ribbon layer. In the present invention, the portion provided with the air blowing holes at the most downstream side of the cooling cylinder is collectively referred to as a cooling air blowing portion.

  In the cooling cylinder, the speed of the cooling air flow direction in the resin running direction of the cooling air at the cooling air outlet is over the whole area in the direction upstream of the air blowing hole in the cooling air flow direction and intersecting the cooling air flow direction. Means are installed to control the distribution. Thereby, the pressure distribution inside the cooling cylinder can be made uniform and the momentum of the cooling air blown out from the delivery hole can be moderated. That is, it is possible to control the speed distribution of the cooling air in the resin running direction in the cooling air blowing part within a range as described later.

  As such a control means, a porous member is used, and specifically, a punching plate 11 or a mesh 12 installed in an air introduction portion of a cooling cylinder element as shown in FIG. When these perforated plates or meshes are used, it is necessary to give a certain amount of flow resistance to the cooling air, so it is preferable to use those having an aperture ratio of 50% or less. The aperture ratio is a value obtained by dividing the aperture area of the porous plate or mesh in a plane perpendicular to the air flow direction by the flow area of the air introduction portion of the cooling cylinder element, and is an arbitrary cross section of the porous member. It is sufficient that the hole area ratio is 50% or less.

  When such a speed distribution control means is not used, the cooling air sent into the cooling cylinder from the cooling air introduction part at the lower part of the cooling cylinder goes straight in the central part of the cooling cylinder, flows upward, and proceeds on the back surface of the upper lid. The direction is changed, and the air is blown out from the top of the cooling cylinder. Therefore, the cooling air velocity distribution from the cooling cylinder at this time tends to be as shown in FIG.

  On the other hand, when a porous member is installed in the cooling air flow path upstream of the air blowing hole in the cooling air flow direction and across the entire direction intersecting the cooling air flow direction, the cooling air sent to the cooling cylinder is porous. In the conventional technology, the cooling air flow that travels straight through the central part of the cooling cylinder in the conventional technology is dispersed, and the cooling air can easily flow even in the horizontal direction of the cooling cylinder. Pressurize. As a result, it becomes possible to obtain a relatively uniform cooling air distribution in the longitudinal direction of the cooling cylinder as shown in FIG. 5, and an air velocity distribution of the cooling air satisfying the following relational expression can be obtained at the cooling air blowing portion. . In addition, the image figure of the wind speed distribution shown with the following relational expression is shown in FIG. 4 to 6, the vertical axis represents the position in the length direction of the cooling air blowing portion, and the horizontal axis represents the wind speed of the cooling air blown from the cooling cylinder.

V _jmax ≦ 25.0 (m / sec)
│V _a -V _j │ <0.14 × V _a
However,
V _j is the wind speed at any part in the range of 5% or more and less than 70% of the total length of the cooling air blowing part from the uppermost end of the cooling air blowing part in the resin running direction
V _jmax is the maximum value of V _j
V _a is the average wind speed in the range from 5% to less than 70% of the total length of the cooling air blowing part from the uppermost end in the resin running direction of the cooling air blowing part. As a result, ultrafine yarn with particularly excellent uniformity is produced. It becomes easy. The molten resin discharged from the spinneret is solidified by the cooling air blown from the cooling cylinder to form a thread, but if the speed of the cooling air blown from the air blowing port is too strong at this time, the resin in the solidifying process is increased. If it is too weak, it will cause unevenness in solidification among the filaments due to insufficient cooling, and it tends to become fineness spots. Therefore, it is necessary to keep the cooling air speed at such a level that the yarn is not greatly shaken until all the filaments are solidified. Immediately after the resin is discharged from the die, the viscosity of the resin is low and the resin is easily shaken by the cooling air. Therefore, as shown in FIG. 6, it is necessary to have a uniform wind speed distribution in the resin direction. The cooling air blowing portion of the cooling cylinder is provided over 150 mm or more in the resin running direction in order to reliably cool and solidify the resin. Preferably it is. On the other hand, if this distance is too long, the spinning operation is likely to be hindered. Therefore, the distance is preferably 300 mm or less.

  Further, the cooling air just after being blown out from the cooling cylinder is rectified as described above. However, as it goes through the outside air, the diffusion direction of the cooling air becomes non-uniform and the rectifying property is lost. For this reason, when the distance between the resin and the cooling cylinder is large, it is difficult to cool the resin uniformly. Therefore, the distance between the resin and the cooling air blowing part is preferably 15 mm or less.

  Furthermore, the air flow outside the running resin is also important. Therefore, as shown in FIG. 1, it is preferable to install an outer cylinder 6 having a length similar to that of the cooling cylinder 5 below the spinneret 4 and outside the traveling filament 4.

  This outer cylinder operates as follows. That is, the unsolidified resin discharged from the spinneret hole is accelerated to the take-up speed while being cooled and solidified by the cooling air blown from the cooling cylinder, so that the resin travels from the middle of the cooling cylinder downward along the resin running direction. Accompanying airflow is generated. By the generation of the accompanying airflow, the air near the bottom of the base to the upper part of the cooling cylinder is dragged, resulting in an air starvation state. As a result, when the outer cylinder is not installed, as shown in FIG. 7, outside air around the spinning machine is sucked into the space, and cooling spots are easily generated. However, as shown in FIG. 8, when the outer cylinder 6 is installed, the outer cylinder blocks the lower surface of the base to the upper portion of the cooling cylinder and the outside, so that it is difficult for outside air to flow into the space and stable cooling can be achieved.

  As shown in FIG. 9, when the inner diameter of the outer cylinder is too large, outside air easily flows from the lower part of the outer cylinder to the vicinity of the upper part of the cooling cylinder along the inner wall of the outer cylinder, while the inner diameter of the outer cylinder is small. If the thread is too long, the yarn will be fused at the time of yarn breakage or preparation for spinning, which makes the operation difficult.Therefore, in order to perform more stable cooling and simplify the operation, the inner diameter of the outer cylinder and the position of the filament are It is more preferable to satisfy the following relational expression.

1.20d <D <1.45d
However, d is the maximum diameter of the approximate circle formed by connecting the spinning holes arranged in an annular shape, and when there are a plurality of annularly arranged spinning holes on the concentric circle, the diameter of the circle is the largest. D is the inner diameter of the outer cylinder.

(Measurement method of wind speed)
The wind speed was measured by bringing an anemone master manufactured by KANOMAX into close contact with the cooling air outlet at each measurement point. The measurement points are at distances of 0, 10, 30, 50, 100, 150, and 200 mm from the upper end of the cylinder that forms the cooling air outlet (measurement at a position 200 mm from the upper end is only when the cylinder is 200 mm), respectively. Four points were measured at 90 ° angles in the circumferential direction, and the average wind speed at these four points was taken as the wind speed at each distance from the upper end of the cooling air outlet.

(Measurement method of Wooster spots)
Wooster spots were measured using a ZELLWEGER USTER USTER TESTER UT-4 at a yarn speed of 50 m / min, Z twist, 8000 rpm for 3 minutes, 1/2 inch.

Example 1
The nylon 6 polymer is melt-spun at 260 ° C. using the apparatus shown in FIG. 1, the yarn is focused 800 mm below the base surface, a spinning oil is applied, and a 56 dtex, 98 filament yarn is wound at a winding speed of 4600 m / Rolled up in min. At this time, the cooling air blown from the cooling cylinder is blown by blowing the cooling air at a temperature of 18 ° C and a humidity of 70% RH so that the differential pressure between the inside of the cooling cylinder and the atmospheric pressure is 200 Pa. To cool the resin. The wind speed at the cooling air blowing part at that time was measured. In addition, Wooster spots representing the fineness uniformity in the longitudinal direction of the obtained yarn were measured.

  The spinneret used was one in which 49 spinning holes with a diameter of 0.15 mm were arranged at equal angles on two concentric circles.

  The cylinder constituting the cooling air blowing part of the cooling cylinder has a thickness of 4.6 mm, and the distance (yarn to cooling cylinder distance) from the filament discharged from the spinning hole installed on the outermost periphery is 9.0 mm. Fuji filter Fujibon made of a phenolic resin-impregnated cellulose ribbon having a small diameter and a hole with a filtration accuracy of 40 μm in a resin running direction of 150 mm was spirally wound into a cylindrical shape.

  In addition, a punching plate having an aperture ratio of 40.3% with a hole having a diameter of 2.0 mm as shown in FIG. 3 was disposed at the upstream end of the cylinder in the cooling air flow direction.

  Further, an outer cylinder having an inner diameter of 118 mm and a length of 78 mm was installed below the spinneret and on the outer periphery of the running resin.

  The results are shown in Tables 1 and 2.

(Example 2)
The point that melt-spun nylon 66 polymer at 285 ° C, the point that has a blower hole over 200 mm in the resin running direction as the cylinder constituting the cooling air blowing part, and the difference between the inside of the cooling cylinder and atmospheric pressure Spinning was carried out in the same manner as in Example 1 except that the cooling air was pressurized and blown so that the pressure was 350 Pa, and the wind speed at the cooling air outlet was measured. The results are shown in Tables 1 and 2.

(Example 3)
Spinning was performed in the same manner as in Example 1 except that the cooling air was pressurized and blown so that the differential pressure between the inside of the cooling cylinder and the atmospheric pressure was 350 Pa, and the wind speed at the cooling air outlet was measured. The results are shown in Tables 1 and 2.

(Comparative Example 1)
Spinning was carried out in the same manner as in Example 1 except that the punching plate was not provided, and the wind speed at the cooling air blowing portion was measured. The results are shown in Tables 1 and 2.

(Comparative Example 2)
Spinning was performed in the same manner as in Example 2 except that the punching plate was not provided, and the wind speed at the cooling air outlet was measured. The results are shown in Tables 1 and 2.

  As apparent from these results, in the examples, the fineness uniformity in the longitudinal direction of the yarn was improved. Wooster spots are an important parameter for judging the quality of the produced filaments, and the higher the Wooster value, the worse the physical properties and appearance uniformity of the fabric in the final fabric. For yarns in the single filament fineness range of ordinary filaments, if the value of Wooster spots is 0.80% or less, there is no problem in quality due to Wooster spots in the fabric. In the microfilament yarns of Comparative Examples 1 and 2 obtained by the conventional technique, the value of Wooster spots usually exceeded 0.80%, but in Examples 1 to 3 using the method of the present invention, the value of Wooster spots was A filament yarn of 0.80% or less that can be safely dyed was produced.

It is a schematic longitudinal cross-sectional view of the melt spinning apparatus which shows one Embodiment of this invention. It is the figure which looked at the melt spinning apparatus shown in FIG. 1 from the downward direction of the cooling cylinder 5. It is the schematic of the porous member installed in the cooling cylinder and the whole area of a cooling wind flow path upstream of a ventilation hole with respect to the cooling wind flow direction, and the direction which cross | intersects a cooling wind flow direction. FIG. 6 is a velocity distribution diagram of cooling air when the cooling air velocity control means is not used. FIG. 6 is a velocity distribution diagram of cooling air when cooling air velocity control means is used. It is an image figure of the velocity distribution of the cooling air when using the cooling air velocity control means. It is a schematic diagram which shows the flow of the external air in a melt spinning apparatus without an outer cylinder. It is a schematic diagram which shows the flow of the external air in the melt spinning apparatus which has an outer cylinder. It is a schematic diagram which shows the flow of the external air in the melt spinning apparatus which attached the outer cylinder with a large internal diameter.

Explanation of symbols

1: Pack housing 2: Spinneret 3: Spinning hole 4: Filament 5: Cooling cylinder 6: Outer cylinder 7: Refueling guide 8: Cooling air blowing part 9: Upper lid 10: Base 11: Punching plate 12: Mesh

Claims (3)

A spinneret having a plurality of spinning holes arranged annularly, and a cooling cylinder disposed below the spinning nozzle and inside the thermoplastic resin spun from the annularly arranged spinning holes. In the melt spinning apparatus, the cooling cylinder has a cooling air blowing portion having a plurality of blowing holes, and the air velocity distribution of the cooling air in the cooling air blowing portion satisfies the following relational expression. A melt spinning apparatus characterized by that.
V _jmax ≦ 25.0 (m / sec)
│V _a -V _j │ <0.14 × V _a
However,
V _j is the wind speed at any part in the range of 5% or more and less than 70% of the total length of the cooling air blowing part from the uppermost end of the cooling air blowing part in the resin running direction
V _jmax is the maximum value of V _j
V _a is the average wind speed in the range from 5% to less than 70% of the total length of the cooling air blowing part from the uppermost end of the cooling air blowing part in the resin running direction   2. The cooling cylinder has a porous member provided over the entire area of the cooling air flow path upstream of the air blowing hole in the cooling air flow direction and intersecting the cooling air flow direction. Melt spinning equipment. A spinneret in which a plurality of spinning holes are annularly arranged, and a plurality of blower holes disposed below the spinneret and inside the resin spun from the annularly arranged spinning holes. Using a melt spinning apparatus equipped with a cooling cylinder having a cooling air blowing portion and blowing the cooling air from the cooling cylinder so that the wind speed distribution of the cooling air in the cooling air blowing portion satisfies the following relational expression, and melt spinning: A melt spinning method characterized by solidifying the obtained resin.
V _jmax ≦ 25.0 (m / sec)
│V _a -V _j │ <0.14 × V _a
However,
V _j is the wind speed at any part in the range of 5% or more and less than 70% of the total length of the cooling air blowing part from the uppermost end of the cooling air blowing part in the resin running direction
V _jmax is the maximum value of V _j
V _a is the average wind speed in the range from 5% to less than 70% of the total length of the cooling air blowing part from the uppermost end of the cooling air blowing part in the resin running direction

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