JP2017066560A - Melt spinning pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a melt spinning pack capable of obtaining a homogenized line of thread with good yarn-making performance by discharging the thread from a nozzle after homogenizing uneven viscosity due to heat history difference by a porous plate in melt spinning of thermoplastic polymer.SOLUTION: A melt spinning pack is formed by arranging a filter layer, a filter, a porous plate 5 and a nozzle sequentially. The porous plate 5 has multiple open holes 6 that allow polymer to pass through. The open holes 6 are disposed on a circumference of n pieces (n≥2) of concentric circles A1, A2, A3,..., An from a center of an inlet 9 on a polymer inlet 9 side and on a circumference of m pieces (m≥1) of concentric circles B1, B2, B3,..., Bm from a center of an outlet 10 on a polymer outlet 10 side. Adjacent open holes 6 disposed on one circumference of the polymer outlet 10 lead to another circumference of the polymer inlet 9. The polymer passed through the open holes 6 is discharged into a polymer reservoir immediately below the porous plate 5 and subsequently transported to the nozzle.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a melt spinning pack used in a process for producing a fiber for melt spinning a thermoplastic resin. More specifically, the present invention relates to a melt spinning pack that makes it possible to homogenize the viscosity unevenness caused by the difference in heat history of the molten polymer and supply it to the nozzle discharge holes, thereby obtaining good yarn-making properties with uniform quality.

  In general, for the production of fibers for melt spinning thermoplastic resins, the raw material chips are melt kneaded with an extruder to form a raw material polymer, which is led to a melt spinning pack via a pipe. The introduced polymer passes through a filter layer composed of a filter medium and a filter for removing foreign matters, is distributed by a perforated plate, and the polymer is spun from a discharge hole of a die to obtain fibers.

Since the thermoplastic polymer is spun at a high temperature of about 300 ° C., naturally, the quality is uneven due to the thermal history. The unevenness of quality due to the heat history requires high-temperature spinning (for example, a high-viscosity polymer for obtaining high strength) for high-viscosity polymers, and the smaller the discharge amount, the longer the residence time from melting to discharge (for example, the finer (Fine monofilament) becomes longer. As a matter of course, these types of products are subject to thermal deterioration due to the difference in thermal history, and the quality unevenness is magnified. Further, when the flow of the polymer is poor, the quality unevenness is promoted and amplified by an abnormal retention portion.
Various studies have been made on a melt spinning pack that minimizes the deterioration of the polymer, and has high quality and good spinning performance.

For example, Patent Document 1 discloses a technique for reducing the breakage of the polymer in the melt spinning pack and reducing the breakage of the stay, thereby extending the replacement cycle of the melt spinning pack.
This uses a mixing block in which a plurality of cylindrical polymer passages are arranged to mix the molten polymer in the melt spinning pack, and the plurality of polymer passages are on a single circumference from the center line of the mixing block. It becomes the structure arrange | positioned at equal intervals.

  However, in such a configuration in which all the cylindrical polymer passages are at the same distance from the center line, the mixing effect of the polymer having uneven viscosity caused by the thermal history difference is insufficient.

  Further, in Patent Document 2, in a base composed of two pieces, an upper base and a lower base, polymers from two or more polymer inflow holes are collected by the polymer transition flow path and flow into the discharge holes. The base technology to be used is disclosed. This is to identify the polymer staying part in the base and to make a number of holes in order to reduce it. Two threads from one base (for example, a fiber having a total fineness of 25 dtex and three single yarns from the left side of the base) In order to increase the productivity by spinning fibers with the same total fineness and the same number of single yarns from the right side of the die, a moderate effect is recognized, but the viscosity unevenness due to a slight difference in heat history In order to make it uniform, a great effect cannot be obtained.

  In the manufacturing process of the fiber for melt spinning the thermoplastic resin, if the viscosity unevenness is caused by the difference in thermal history in the spinning pipe of the polymer, particularly in the spinning pack / die, the fluidity becomes non-uniform. When such a polymer having viscosity unevenness is mixed into the yarn, even if the viscosity unevenness is very small, the yarn is very thin, resulting in quality unevenness and inducing yarn breakage during spinning. Various studies have been made to reduce and eliminate such polymer viscosity unevenness, but the present situation is not yet satisfactory.

  In recent years, in particular, there has been an increasing demand for finer monofilaments, higher strength, and higher quality. There has been a long-awaited technology that satisfies these requirements, has a uniform quality, and provides good spinning properties.

JP 2008-38278 A Japanese Utility Model Publication No. 60-97778

  The present invention has reached the present invention as a result of intensive studies in order to solve the problems of the prior art. That is, an object of the present invention is to provide a melt spinning pack that makes it possible to homogenize the viscosity unevenness caused by the difference in thermal history of the molten polymer and supply it to the die discharge hole, thereby achieving uniform yarn quality and good spinning properties. It is to provide.

That is, this invention consists of the following structures.
1. In a melt spinning pack in which a filter layer, a filter, a perforated plate, and a die are sequentially arranged, the perforated plate has a plurality of through holes through which the polymer passes, and the through holes are introduced on the polymer introduction port side. A plurality of n (n ≧ 2) concentric circles A1, A2, A3,..., An from the center of the mouth surface, respectively, and on the polymer outlet side, m from the center of the outlet surface. A plurality (m ≧ 1) of concentric circles B1, B2, B3,..., Bm are arranged on the circumference, and adjacent through-holes arranged on one circumference of the polymer discharge port surface are A melt spinning pack characterized in that the polymer passing through different circumferences of the polymer introduction port surface and passing through the through hole is discharged into a polymer reservoir directly under the perforated plate and then transferred to the die.
2. 2. The melt spinning pack according to claim 1, wherein the concentric circle number (n) of the introduction port surface of the perforated plate and the concentric circle number (m) of the discharge port surface satisfy n> m 2.
3. The melt spinning pack according to claim 1 or 2, wherein the number of concentric circles (m) on the discharge port surface of the perforated plate is one.

  The melt spinning pack of the present invention allows polymers having different heat histories to be discharged from the adjacent discharge ports on the polymer discharge port surface of the perforated plate, so that the discharged polymers can reach the polymer introduction port from the polymer reservoir to the base inlet. Can be mixed uniformly. By adopting such a configuration, the present invention does not depend on the fluid behavior of the polymer, and ensures uniform mixing.

  By using a melt spinning pack incorporating such a perforated plate of the present invention, viscosity unevenness caused by a difference in the thermal history of the molten polymer can be eliminated, and the molten polymer can be homogenized and supplied to the die discharge holes, thereby achieving homogeneity. It becomes possible to stably obtain a yarn having excellent yarn forming properties.

FIG. 1 is a schematic view showing an example of an embodiment of the melt spinning pack of the present invention. FIG. 2 is a schematic view for explaining a through hole, an introduction port, and a discharge port of the porous plate of the present invention. FIG. 3 is a schematic diagram in which the number of concentric circles (n) on the inlet port surface and the number of concentric circles (m) on the outlet port surface are n> m and m = 1.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing an embodiment of the melt spinning pack of the present invention, FIG. 2 is a schematic view for explaining through holes, inlets and outlets of the porous plate of the present invention, and FIG. The number of concentric circles (n) and the number of concentric circles (m) on the discharge port surface are schematic diagrams of n> m and m = 1.

  In FIG. 1, 1 is a schematic configuration diagram of a melt spinning pack, 2 is a melt polymer supply port, 3 is a filter layer section, 4 is a filter, 5 is a perforated plate, 6 is a through hole, 7 is a polymer reservoir, 8 Is a base, 9 is an inlet, and 10 is an outlet.

  Briefly explain the flow of the polymer. The polymer supplied to the pack part passes through the filter layer part 3 composed of fine sand in order to filter impurities from the supply port 2. Further, impurities that have passed without being captured by the sand layer are finally captured by the filter 4. The cleaned polymer is sent to the perforated plate 5. Here, the polymer passes from the introduction port 9 to the discharge port 10 of the through holes 6 formed in the perforated plate 5. The polymer that has passed through the perforated plate 5 is once collected in the polymer reservoir 7 and then guided to the base 8.

FIG. 2 is a schematic diagram shown for easy understanding of the introduction port 9 and the discharge port 10 of the through hole 6 disposed in the perforated plate 5. The upper side of the figure shows the introduction port surface, and the lower side shows the discharge port surface. A1, A2,..., An indicate the circumference where the introduction port is disposed. B1, B2,... Bm indicate the circumferences where the discharge ports are arranged. The relationship between the number n of the circumference in which the 9 inlets are perforated and the number m of the circumference in which the 10 outlets are perforated may be the same, but n> m Thus, as will be described in detail below, the effect is more exhibited.
Hereinafter, the flow and mixing state of the polymer will be described in detail with reference to FIG.

The polymer that has passed through the filtration part and the filter is an introduction port (A1-1) of through holes arranged on the circumference of n (n ≧ 2) A1, A2,..., An from the center of the perforated plate. , A1-2, ... An-3, ...). And the polymer is discharged from the through holes (B1-1, B1-2, B1-3, Bm) arranged on the circumference of m pieces (m ≧ 1) B1,..., Bm from the center.・ ・）
Here, adjacent discharge ports B1-1, B1-2, and B1-3 disposed on one circumference B1 of the discharge port surface are respectively the introduction ports A2-1 and A1 having different circumferences of the introduction port surface. -2, An-3 (in this case, n is not 1 or 2). In this way, the polymer flows from the different circumferential rows of the introduction port surface to the discharge port arranged adjacent to one circumference of the discharge port surface, and then merges in the polymer reservoir, By being guided to the die, the molten polymer is forcibly mixed, and the viscosity unevenness caused by the difference in thermal history is greatly reduced by this mixing. The number n of the circumferences where the introduction ports are arranged and the number m of the circumferences where the discharge ports are arranged may be the same, but if n> m, on one circumference of the discharge port surface, More discharge ports are provided, which is preferable because mixing becomes more effective. Furthermore, m = 1 is preferable. As described above in detail, each of the polymers on the circumference arranged at positions away from the center of the introduction port surface has a slight difference in thermal history. It will be. In the present invention, the polymer at a position close to the center of the perforated plate and the polymer at a position far from the center are forcibly joined and mixed on the discharge port surface, and the number of circumferences where the introduction ports are arranged is increased. By reducing the number of circles around which the outlets are arranged, the mixing of the polymers is further promoted to bring it closer to the ideal state. By transferring the homogenized polymer to the die, there is little unevenness in viscosity, and fibers with good quality and yarn-making property can be obtained.

  FIG. 3 is a schematic diagram in which the number of circumferences where the discharge ports of the perforated plate are arranged is 1. This is particularly preferably used for fiber applications that require a small amount of polymer discharge, high viscosity, high strength, and high quality.

  As is apparent from FIG. 3, the polymer that has passed through the through holes from the plurality of circumferences A1, A2,... An on the introduction port surface is discharged onto one circumference B1 on the discharge port surface. As a matter of course, only the polymers from the inlets having different circumferences of the inlet ports are arranged to be adjacent to each other at the outlet. By adopting such a configuration, it becomes possible to obtain a fiber that satisfies the requirements of high viscosity, high strength, and high quality with a small discharge amount.

The thermoplastic resin used in the present invention is not particularly limited as long as it is a thermoplastic resin that can be melt-spun. Examples thereof include polyesters typified by polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polylactic acid, polyethylene naphthalate, polyamides typified by nylon 6, nylon 66, and the like, and polyphenylene sulfide. Among them, in particular, the melt spinning pack of the present invention can give good results in the production of polyester fibers mainly composed of polyethylene terephthalate. A copolymer component may be added to the thermoplastic resin as long as the effects of the present invention are not impaired. In the case of a polyester-based thermoplastic resin, examples of copolymer components include acid components such as isophthalic acid, phthalic acid, dibromoterephthalic acid, naphthalene dicarboxylic acid, diphenylxyentanecarboxylic acid, and oxyethoxybenzoic acid. Examples thereof include bifunctional aliphatic carboxylic acids such as functional aromatic carboxylic acids, sebacic acid, adipic acid, and oxalic acid, and cyclohexanedicarboxylic acid. Examples of the glycol component include propanediol, butanediol, neopentyl glycol, bisphenol A, and polyoxyalkylene glycols such as polyethylene glycol and polypropylene glycol. Furthermore, antioxidants, antistatic agents, plasticizers, ultraviolet absorbers, colorants, and the like may be added as appropriate as additives.

  Intrinsic viscosity (hereinafter referred to as IV) when spinning a polyester resin using the melt spinning pack of the present invention is preferably 0.4 or more, and more preferably, because a high-strength, high-elasticity fiber can be obtained. Is 0.6 or more. On the other hand, it is preferably 1.4 or less, and more preferably 1.2 or less, from the viewpoint of the fluidity of the molten polymer in melt spinning.

  The material of the perforated plate is not particularly limited, but it depends on the melting temperature and the temperature when washing the perforated plate with the polymer attached after spinning (about 400 ° C.) and the filtration layer during spinning. From the viewpoint of being able to withstand pressure (about 30 MPa) and suppressing the generation of rust, stainless steel is preferable.

Although the size of the through hole drilled in the perforated plate is not particularly limited, a plurality of through holes are respectively disposed on the circumference of a plurality of concentric circles from the center of the inlet port surface and the outlet port surface, The hole diameter is preferably 1 to 5 mm from the viewpoint of avoiding excessive pressure loss when the polymer passes through the through hole.
In addition, in providing a plurality of concentric circles from the center of the inlet port surface and the outlet port surface, from the viewpoint of discharging polymers having different heat histories on the inlet port surface from adjacent outlet ports, The difference is preferably 1 to 40 mm.

  In addition, the number of through-holes arranged on the circumference of a plurality of concentric circles from the center of the inlet port surface and the outlet port surface can be reduced from the viewpoint of reducing polymer retention on the inlet port surface and outlet port surface. Needless to say, the larger the number, the better.

  Next, the manufacturing method of the polyethylene terephthalate monofilament using this invention is demonstrated as an example. The polyethylene terephthalate monofilament manufacturing process consists mainly of melting polyethylene terephthalate, discharging it from the die, cooling it, and drawing it with a roller at a constant speed. It is divided into three steps: a winding process for winding the strip.

  The spinning process may employ a known melt spinning method. Polyethylene terephthalate melted by an extruder is supplied to the melt spinning pack of the present invention using a metering pump so as to obtain a desired fineness, and the yarn is discharged. . The melt spinning temperature is preferably 280 to 310 ° C. from the viewpoint of sufficiently melting polyethylene terephthalate and suppressing thermal decomposition due to excessive heat application. For the purpose of suppressing the orientation of the yarn and making the orientation uniform, a heating cylinder may be used at a site until the discharged yarn is cooled. When using a heating cylinder, it is preferable that the atmosphere temperature in a heating cylinder shall be 250 degreeC or more. If the temperature inside the heating cylinder is 250 ° C. or higher, the effect of the heating cylinder is sufficiently obtained, and the orientation can be suppressed and made uniform. As a cooling method, it is preferable to employ cooling by chimney air. For the cooling by chimney air, for example, a method of spraying from a direction substantially perpendicular to the running direction of the yarn from one direction or a method of blowing from a direction substantially perpendicular to the running of the yarn and from the entire circumferential direction can be used. It is preferable to apply a spinning oil before taking out the cooled yarn with a roller. The composition of the spinning oil is not particularly limited, but an oil containing 30% or more of a fatty acid ester-based smoothing agent is preferably used from the viewpoint of improving smoothness and suppressing thread fluff during weaving. Moreover, it is preferable to add about 0.1 to 5% of polyether-modified silicone in the oil because the smoothness is further improved. The oil agent may be mixed and emulsified with water and applied to the yarn with an oiling guide or an oiling roller. In this case, the amount of oil supply is preferably 0.1 to 1.0 wt% with respect to the drawn yarn because smoothness is good and yarn drop and collapse during package formation are suppressed. The fed yarn is preferably taken up by a take-up roller having a surface speed of 300 to 3000 m / min. Thereafter, either a two-step method in which the yarn is once wound as an undrawn yarn and then drawn, or a direct spinning drawing method in which the yarn is supplied to the drawing step as it is may be used.

In the stretching process, for the purpose of uniform stretching, a hot roller that heats the yarn to a temperature above the glass transition point, and a method in which the surface speed is higher than that of the hot roller and the hot roller that is heated to a temperature higher than the crystallization temperature is sequentially drawn and stretched. Is preferred. What is necessary is just to select the temperature and draw ratio of a hot roller according to the target physical property. For example, when obtaining high strength and high modulus, the surface temperature of the final roller is preferably 120 ° C. or higher, and the draw ratio is preferably 3 to 6 times. In addition, it is more preferable to install a hot roller between the hot rollers so as to perform so-called multistage stretching because the stretching uniformity is improved. In the case of multistage stretching, the first stage draw ratio is 0.6 to 0.9 times the total draw ratio. Further, a cold roller may be provided between the final hot roller and the winding unit. When the speed of the cold roller is faster than the final hot roller, the resulting monofilament has a higher modulus. When the speed of the cold roller is lower than that of the final hot roller, the modulus of the obtained monofilament is reduced, but the stress difference during wet heat shrinkage is reduced, and thread fluff during weaving is less likely to occur. The speed difference between the final hot roller and the cold roller may be adjusted according to desired characteristics. The speed of the cold roll is preferably -7 to 2% with respect to the speed of the final hot roller.
In the winding process, the drawn monofilament is wound up, but the winding method is not particularly limited as long as a desired package is obtained.

  Hereinafter, the present invention will be described in detail with reference to examples. The evaluation in the examples followed the following method.

(1) Intrinsic viscosity (IV)
0.8 g of a sample polymer was dissolved in 10 mL of o-chlorophenol having a purity of 98% or more at a temperature of 25 ° C., and a relative viscosity ηr was determined by the following equation using an Ostwald viscometer at a temperature of 25 ° C. Using this relative viscosity ηr, the intrinsic viscosity (IV) was calculated by the following formula.
ηr = η / η0 = (t × d) / (t0 × d0)
Intrinsic viscosity (IV) = 0.0242 ηr + 0.2634
here,
・ Η: Viscosity of polymer solution ・ η0: Viscosity of o-chlorophenol t: Dropping time of solution (second)
d: density of the solution (g / cm ³ )
t0: o-chlorophenol drop time (seconds)
d0: density of o-chlorophenol (g / cm ³ )
(2) Fineness fluctuation rate U% (H)
Using a Worcester tester UT-4CX manufactured by Twelvegar Worcester, half inert (U hi%) was measured under the following measurement conditions.

Yarn feeding speed: 200 m / min Measuring yarn length: 200 m
Twister: None Mears. slot: 0.18 mm
Next, the result of applying the melt spinning pack of the present invention is shown.

Example 1
Polyethylene terephthalate containing 0.3 wt% of titanium oxide with an intrinsic viscosity (IV) of 0.8 polymerized and pelletized by a conventional method was melted by a pressure melter.

  Thereafter, the melted polymer was passed through a pipe provided in a spin block kept at 293 ° C. and a metering pump for metering to a desired polymer flow rate, and led to the melt spinning pack of the present invention to spin the yarn. .

  Thereafter, air at 25 ° C. from one direction and substantially perpendicular to the yarn was blown onto the yarn at a wind speed of 20 m / min using a cooling machine to cool and solidify. The spinning oil was supplied to the cooled and solidified yarn by an oiling roll so that the amount of the spinning oil became 0.3 wt% with respect to the drawn yarn.

The component of the oil agent is 50 wt% of a known fatty acid ester-based smoothing agent, wt1% of a water-soluble polyether-modified silicone, and 10 wt% of a mixed oil agent composed of a known metal wear agent, antistatic agent, and surfactant with respect to distilled water. % Emulsified.
The yarn after refueling was taken up as it was with a take-up roll having a surface speed of 800 m / min, and then the undrawn yarn was once wound up.
Thereafter, the polyethylene terephthalate monofilament package was obtained by drawing and winding with a drawing machine comprising a yarn feeding roll, first, second and third hot rolls, cold roll, and draw twister type winder. The detailed conditions at that time are as follows.
First hot roll: temperature 90 ° C., surface speed 138 m / min Second hot roll: temperature 90 ° C., surface speed 484 m / min Third hot roll: temperature 140 ° C., surface speed 600 m / min Cold roll: room temperature, surface speed 600 m / Min Draw twister: Spindle speed 8000rpm,
In the melt spinning pack of the present invention, the diameter of the filtration part is 53.5 mm, the nonwoven fabric filter is provided, the number of circumferences where the introduction port of the perforated plate is arranged is 3, and the first closest to the center thereof. Eight inlets on the circumferential diameter of the row 14 mm, 8 inlets on the circumferential diameter 27 mm of the second row, 16 inlets on the circumferential diameter 47 mm of the third row, The number of circumferences in which the outlets are arranged is 1, and on the circumference diameter of 37 mm, the outlets leading to the first row of the inlets, the outlets leading to the third row, the outlets leading to the second row, A total of 32 outlets were arranged in the order of outlets leading to the third row, outlets leading to the first row,. That is, it is a through-hole arrangement in which polymers from different inlets on the circumference are allowed to be adjacent to each other at the outlet. The diameter of the through hole was 2.0 mm, and the material of the porous plate was SUS420J2. The diameter of the polymer reservoir was 39 mm, the thickness was 1.5 mm, and the nozzle was provided with two discharge holes with a diameter of 0.15 mm.

  As a result of confirming the bending of the yarn immediately after the nozzle discharge hole caused by the viscosity unevenness with a long-focus microscope, no bending was observed and the discharge was stable. As a result of continuously spinning 6 dtex monofilament for 72 hours, there was no yarn breakage and good spinning results were obtained. Moreover, as a result of measuring U% (H) of the obtained monofilament, it was 0.8% or less and was a good polyester monofilament.

Comparative Example 1
The number of peripheries in which the inlets of the perforated plate are arranged is 3, and there are six inlets on the circumferential diameter 14 mm of the first row closest to the center thereof, and the circumferential diameter of the second row 27 mm above There are eight inlets, sixteen inlets are arranged on the third row with a circumferential diameter of 47 mm, and the number of circumferences in which the outlets are arranged is 3, which is the first closest to the center. Six outlets are arranged on the circumferential diameter 14 mm of the row, eight outlets are arranged on the circumferential diameter 27 mm of the second row, and 16 outlets are arranged on the circumferential diameter 37 mm of the third row. The through-hole arrangement was such that the inlet of the row was connected to the outlet of the first row, the inlet of the second row was connected to the outlet of the second row, and the inlet of the third row was connected to the outlet of the third row. Otherwise, polyethylene terephthalate monofilament spinning was performed under the same conditions as in the examples.
As a result of confirming the bending of the yarn immediately after the nozzle discharge hole by visual observation and a long focus microscope, a large bending caused by uneven viscosity was recognized.

  That is, a polymer that has received a large amount of thermal history causes a decrease in viscosity, which increases the flow rate, and a high-viscosity and slow flow rate polymer with little thermal history is pushed and bent by the flow rate difference after the discharge hole where the pressure is released. Is. It can be seen that the polymer is inhomogeneous both in the longitudinal direction and in the cross-sectional direction. As a result, as a result of continuous spinning of 6 dtex monofilament for 72 hours, naturally, yarn breakage frequently occurred and the spinnability was poor. Moreover, as a result of measuring the obtained monofilament U% (H), it was as poor as 1.3% or more, and it was not a polyester monofilament that could withstand precision filter applications.

By using the melt spinning pack incorporating the perforated plate of the present invention, it is possible to homogenize the viscosity unevenness caused by the difference in the thermal history of the molten polymer and supply it to the nozzle discharge hole, and to stabilize the yarn with excellent quality and good threadability. Can be obtained.

1: Configuration diagram of melt spinning pack
2: Molten polymer supply port
3: Filter layer
4: Filter
5: Perforated plate
6: Through hole
7: Polymer reservoir
8: Cap
9: Perforated plate inlet
9-A1: Circumferential introduction groove row number and through-hole number 9-B1: Same as above 9-C1: Same as above 10: Perforated plate discharge port 10-A1: Circumference discharge row number and discharge port number 10-B2 : Same as above 10-B3: Same as above

Claims (3)

  In a melt spinning pack in which a filter layer, a filter, a perforated plate, and a die are sequentially arranged, the perforated plate has a plurality of through holes through which the polymer passes, and the through holes are introduced on the polymer introduction port side. A plurality of n (n ≧ 2) concentric circles A1, A2, A3,..., An from the center of the mouth surface, respectively, and on the polymer outlet side, m from the center of the outlet surface. A plurality (m ≧ 1) of concentric circles B1, B2, B3,..., Bm are arranged on the circumference, and adjacent through-holes arranged on one circumference of the polymer discharge port surface are A melt spinning pack characterized in that the polymer passing through different circumferences of the polymer introduction port surface and passing through the through hole is discharged into a polymer reservoir directly under the perforated plate and then transferred to the die.   2. The melt spinning pack according to claim 1, wherein the concentric circle number (n) of the introduction port surface of the perforated plate and the concentric circle number (m) of the discharge port surface satisfy n> m 2.   The melt spinning pack according to claim 1 or 2, wherein the number of concentric circles (m) on the discharge port surface of the perforated plate is one.

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