JP2000248418A - Nozzle pack for spinning and production of cellulose acetate fiber yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nozzle pack for spinning capable of suppressing the temperature difference of a spinning solution between the vicinity of a peripheral wall and the central part in the nozzle pack and maintaining the spinning solution at a uniform viscosity. SOLUTION: This nozzle pack 10 for dry spinning is obtained by installing an introduction part 11c for a spinning solution in the upstream part and arranging a spinneret 13 having many spinning holes in a discharging part 11d on the downstream end and further providing a branching plate 17 for changing the flow direction of the spinning solution and branching the spinning solution with plural branching slits and a constricted part 14a for rejoining the branched spinning solution in the interior of the spinning pack 10. The spinning solution is passed through the branching slits, rejoined in the constricted part 14a and thereby kneaded to uniformize the temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle pack for spinning, and more particularly to a nozzle pack for spinning suitable for dry spinning of cellulose acetate and the like, and a method for producing a cellulose acetate fiber yarn having less unevenness in fineness.

[0002]

2. Description of the Related Art Fiber yarns composed of cellulose derivatives, for example, cellulose acetate fiber yarns, are generally
The cellulose derivative is dissolved in a soluble solvent, and if necessary, a spinning dope containing an optional additive such as titanium oxide is discharged from a spinneret having several hundred or more spinning holes. It is manufactured by a dry spinning method in which a solvent is evaporated and solidified into fibers.

In this dry spinning, the spinning solution is extruded from a spinning hole of a spinneret into a heated spinning tube through which a heated gas flows, and the solvent in the spinning solution is evaporated by heating. At this time, since the spinning solution is desirably heated immediately after being extruded from the spinning hole, generally, a nozzle pack having the spinning hole at a downstream end is arranged at an upstream portion in the spinning cylinder, and A heating gas is introduced into the spinning cylinder from an upstream side of the spinning hole.

[0004] As described above, in dry spinning, a spinning stock solution is extruded into a heated gas stream to evaporate a solvent from the stock solution.
In the obtained fiber yarn, unevenness of fineness and yarn breakage easily occur between single yarns. Therefore, conventionally, various proposals have been made regarding the introduction of the heated gas in order to reduce such unevenness in fineness between single yarns and yarn breakage. For example, JP-A-61-282408
Japanese Patent Application Laid-Open No. 62-78207 and Japanese Patent Application Laid-Open No. 62-78207 propose a method for optimizing the method of introducing the heated gas in dry spinning.

In the dry spinning apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 61-282408, a plurality of spinning nozzles are concentrically formed by a spinning nozzle holder, and a hot gas introduction pipe is provided at the center of the circle. Are supported on the same plane. Further, the spinning nozzle holder is attached to the upper end of the spinning cylinder. The spinning nozzle holder and the spinning nozzle are separated from the hot gas introduction pipe by a heat insulating layer. Further, the entire device is covered with a heat insulating material.

In the dry spinning method disclosed in Japanese Patent Application Laid-Open No. 62-78207, a plurality of cylindrical spinning nozzles having one or more spinning holes at the lower end are concentrically arranged upstream of the spinning cylinder. The heating gas is introduced at a speed of at least 5 m / sec from the center of the circle. Further, a plurality of plates are arranged below the heated gas inlet in a stepwise manner in a direction orthogonal to the introduced gas. Therefore, the gas introduced into the spinning cylinder is changed in flow once in the radial direction of the spinning cylinder, is divided and then flows along the peripheral wall of the spinning cylinder in the longitudinal direction of the spinning cylinder, i.e., the yarn. The direction is changed to the direction in which the yarn is extruded, and finally the gas is actuated at a speed of 0.5 m / sec from both the center side and the outer peripheral side of the spinning cylinder in a direction parallel to the yarn.

[0007]

However, there is a limit to the reduction of unevenness in fineness between single yarns and yarn breakage due to the above-described change in the method of introducing the heated gas, and further improvement is desired. Therefore, as a result of intensive studies by the present inventors,
Since the nozzle pack is heated from the outside by hot air, the temperature of the nozzle pack significantly increases depending on the size, shape, and spinning conditions of the nozzle pack. Along with that, the stock solution flowing in the nozzle pack also has a difference in heat history between the vicinity of the peripheral wall of the nozzle pack and the central part,
Thereby, it turned out that unevenness of fineness and thread breakage occur. That is, due to the difference in heat history of the spinning dope near the peripheral wall and the central portion of the nozzle pack, the spinning dope is distributed with a different viscosity in the radial direction from the center of the nozzle pack. When the spinning dope is extruded from the spinneret formed at the downstream end of the nozzle pack in a state where the spinning dope is distributed with different viscosities, the spinning dope cannot be discharged uniformly from many spinning holes of the spinneret. In the fiber yarn spun from one spinneret, unevenness of fineness is generated between single yarns, and further, yarn breakage or the like is induced.

Similarly, in the melt spinning, a temperature difference occurs in the spinning dope between the vicinity of the peripheral wall of the nozzle pack and the central portion in contact with the outside air, and the viscosity of the spinning dope differs in the radial direction from the center of the nozzle pack. As in the case of dry spinning, when the spinning solution is spun from each spinning hole with a different viscosity distributed, the resulting fiber yarns may have unevenness of fineness between the single yarns, and frequent yarn breakage. Becomes

The present invention focuses on a new cause of such fineness unevenness and yarn breakage, suppresses the temperature difference of the spinning dope between the vicinity of the peripheral wall of the nozzle pack and the central portion, and makes the spinning dope in the nozzle pack a uniform viscosity. It is an object of the present invention to provide a nozzle pack for spinning which can maintain a low yarn density and to provide a spinning method of a cellulose acetate fiber yarn having a small fineness variation of a single yarn.

[0010]

Means for Solving the Problems In order to achieve the above object, an invention according to claim 1 is a spinning nozzle pack having an introduction section and a discharge section for a spinning solution, wherein the inside of the nozzle pack is The main component of the spinning nozzle pack is a spinning nozzle pack, which includes a branching portion that divides the spinning dope introduced from the introduction portion into a plurality of portions, and a throttle portion that rejoins the split spinning dope. .

In the spinning nozzle pack according to the first aspect of the present invention, the spinning solution introduced into the nozzle pack from the introduction section flows through the nozzle pack toward the discharge section by the branching section. The flow direction is changed and the flow is divided into a plurality. Thereafter, the plurality of spinning dope streams are joined again at the narrowing section, so that the spinning dope is kneaded, the temperature of the spinning dope is averaged from the center of the nozzle pack to the peripheral wall, and the viscosity of the dope becomes uniform. In addition,
The effect of averaging the temperature of the spinning solution and the effect of suppressing the variation in fineness associated therewith become remarkable when the nozzle pack has a discharge surface having a diameter of 30 mmφ or more.

Further, in the invention according to claim 2, the flow dividing portion includes a flow dividing plate arranged to traverse the flow of the spinning solution, and a peripheral edge of the flow dividing plate and an inner peripheral wall of the nozzle pack. A plurality of diverting slits are formed between them. In this way, by passing through a plurality of split slits between the peripheral edge of the split plate and the inner peripheral wall of the nozzle pack, that is, by passing through a narrow gap, the heat history is uniformly applied to the spinning solution passing through the slit from the peripheral wall. Granted.

According to the third aspect of the present invention, the width of the split slit is set to 0.1 to 8 mm. As the slit width is smaller, the effect of kneading the spinning dope and homogenizing the temperature is enhanced, but if the slit width is too small, the pressure in the nozzle pack increases, which is not preferable. Further, according to the invention of claim 4, the depth of the split slit is 4 to 100 mm. This slit depth is deep, that is, the longer the distance that the spinning stock solution comes into contact with the peripheral wall of the nozzle pack, the greater the effect of uniformizing the temperature of the spinning stock solution. Heating becomes large,
The stock solution for spinning may be deteriorated.

According to a fifth aspect of the present invention, the flow dividing plate has a plurality of diversion recesses radially arranged from the center to the periphery on the upstream surface thereof and communicating with the diversion slit. ing. The spinning solution is smoothly and evenly guided to the slit by the diversion recess.

Further, according to the invention of claim 6, the aperture portion has a diameter of 2 to 40 mmφ. The smaller the diameter of the constricted portion, the more uniform the temperature by kneading the combined spinning dope is improved, but if the diameter is too small, the pressure in the nozzle pack increases, which is not preferable. I have.

According to the seventh aspect of the present invention, a filter for a stock solution for spinning is further disposed inside the nozzle pack,
The discharge unit is provided with a spinneret having a plurality of spinning holes. By arranging a spinneret having a plurality of spinning holes in this way, it is possible to spin a multifilament yarn, and at this time, the spinning solution is discharged from each spinning hole with a uniform viscosity, and the single fiber It is possible to obtain a yarn having no fineness unevenness between the yarns.

According to the invention of claim 8, the discharge surface diameter of the discharge section is set to 20 to 200 mmφ. If the discharge surface diameter is smaller than 20 mmφ, it becomes difficult to incorporate the above-mentioned flow dividing plate into the nozzle pack. In general, in view of the limitations of the spinning machine, the discharge surface diameter is suitably set to 200 mmφ. The diameter of the discharge surface is substantially the same as the diameter of the spinning surface of the spinneret.

Further, according to a ninth aspect of the present invention, there is provided a method for producing cellulose acetate fiber yarn by dry spinning, wherein the spinning nozzle pack according to any one of the first to eighth aspects of the present invention is used. Another major configuration is a method for producing a cellulose acetate fiber yarn characterized by the above. According to the ninth aspect of the present invention, since the above-described spinning nozzle pack is used, the temperature of the spinning stock solution in the nozzle pack is averaged from the central portion of the nozzle pack to the peripheral wall portion. Even in a uniform state,
It is discharged from the spinning hole. Therefore, the obtained cellulose acetate fiber yarn becomes an excellent one with very small unevenness in fineness between single fibers, and yarn breakage in the spinning process can be effectively suppressed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings. FIG.
FIG. 2A is a vertical sectional view schematically showing a nozzle pack for dry spinning according to a preferred embodiment of the present invention. FIG. 2A is a top view of a flow dividing plate arranged in the nozzle pack, and FIG. FIG.

The nozzle pack 10 has a pack body 11 composed of a cylindrical pack peripheral wall 11a and a pack upper wall 11b for closing the upper part of the pack peripheral wall 11a. The pack peripheral wall 11a and the pack upper wall 11b are provided. And are connected by a plurality of bolts 12. The pack upper wall 11b has an inlet hole 11c for the spinning dope in the center thereof, and the inner wall surface of the pack upper wall 11b is formed as a tapered surface inclined downward from the inlet hole 11c toward the periphery. I have.

On the other hand, the pack peripheral wall 11a is provided with a spinneret 13 having a plurality of spinning holes at a discharge portion 11d at the lower end thereof. The discharge surface diameter L of the discharge portion 11d is set to 20 to 200 m in consideration of the incorporation of various members described below into the nozzle pack 10 and restrictions in a general spinning machine.
mφ. The discharge surface diameter L is substantially the same as the diameter of the spinneret 13 on the spinning surface.

Further, inside the pack peripheral wall 11a,
A partition plate 14 for vertically partitioning the inside of the peripheral wall 11a is disposed so as to be closely fitted to the peripheral wall 11a. Same partition plate 14
Is formed with a through hole 14a having a diameter of 2 to 40 mm in the center, and the through hole constitutes the narrowed portion 14a of the present invention. In the illustrated embodiment, the upper and lower surfaces of the partition plate 14 are slightly inclined toward the narrowed portion 14a.

The partition plate 14 in the pack body 11
Downstream, that is, the partition plate 14 and the spinneret 1
3, a perforated plate 15 having a large number of holes formed on almost the entire surface is provided, and a filter 16 is placed on the upper surface of the perforated plate 15. On the other hand, on the upstream side of the partition plate 14 in the pack body 11, a flow dividing plate 17 is arranged in a direction crossing the flow of the spinning solution.

As shown in FIG. 2, the flow dividing plate 17 has a substantially disk shape as a whole, and has a ridge 17a formed in a cross shape from the upper surface to the peripheral edge thereof. When the flow dividing plate 17 is accommodated in the pack body 11, the peripheral ridges 17 are provided.
The top surface of a is in contact with the inner peripheral wall surface of the pack body 11, and four distribution slits 17 b are formed between the inner peripheral wall surface and the peripheral edge of the distribution plate 17. The split slit 17b
Slit width W, that is, the protrusion height of the ridge 17a is 0.1.
It is set to 1 to 8 mm.
The slit depth D of b is set to 4 to 100 mm.

Further, the upstream surface of the flow dividing plate 17 is formed with four 1/4 circular concave portions 17c radially extending from the center by the ridges 17a. Each of the branch slits 17b
Is in communication with In the present embodiment, the lower surface of the flow dividing plate 17 is formed as a tapered surface protruding toward the center of the same flow dividing plate 17, and the ridge 17a is also extended to the lower surface. It may be a plane.

When spinning the spinning dope using the nozzle pack 10, the spinning dope is introduced into the pack body 11 through the introduction hole 11c of the pack upper wall 11a. The undiluted spinning solution introduced into the pack body 11 is supplied to the lower discharge unit 1.
While flowing toward 1d, it abuts on the upper surface of the flow dividing plate 17 on the way, and the spinning solution changes its flowing direction toward the periphery of the flow dividing plate 17. At this time, since the diversion recess 17c is formed on the upper edge of the diversion plate 17, the spinning solution is smoothly and uniformly divided and guided to the diversion slit 17b.

The undiluted spinning solution guided to the splitting slit 17b and passing through the slit 17b is heated by heat from the peripheral wall of the pack body 11, and the slit width W of the slit is as small as 0.1 to 8 mm. Therefore, the heating from the peripheral wall of the pack body 11 is performed uniformly.

The four spinning stock flows that have passed through the split slit 17b flow to the narrowing portion 14a and merge again. At this time, the upper surface of the partition plate 14 on which the throttle portion 14a is formed is an inclined surface.
Is formed as a tapered surface protruding toward the center, so that the spinning solution flows smoothly toward the squeezing portion 14a.

As described above, the spinning dope is changed in flow direction by the flow dividing plate 17 and is divided into a plurality of flows. Furthermore, the separated spinning dope is heated evenly when passing through the dividing slit 17b. By being joined again at the narrowed portion 14a, the whole is kneaded and the temperature is averaged. Therefore, the viscosity of the spinning stock solution is also uniform, and the single fibers spun from the respective spinning holes of the spinneret have the same fineness as each other, and an excellent fiber yarn without unevenness in fineness can be manufactured. Also, yarn breakage during spinning is suppressed,
Manufacturing efficiency is also significantly improved.

FIG. 3 shows another flow dividing plate provided in the nozzle pack of the present invention. FIG. 3a is a top view of the same flow plate, and FIG. 3b is a side view of the same flow plate. Dividing plate 2 shown in FIG.
7 also has a substantially disk shape as a whole, and its diameter is the same as the diameter of the inner peripheral wall of the pack body 11. Dividing plate 27
Has a large number of vertical grooves 27b on the peripheral edge thereof, and when the same flow dividing plate 27 is stored in the pack body 11, the grooves 27b diverge between the inner peripheral wall surface of the pack body 11. The slit 27b is formed. Further, on the upstream surface of the flow dividing plate 27, a number of flow dividing recesses 27c are formed radially from the center to the peripheral edge thereof, and the same flow dividing recess 27c communicates with the flow dividing slit 12b. . Note that, also in the present embodiment, the lower surface of the flow dividing plate 27 is formed as a tapered surface protruding toward the center of the same flow dividing plate 27, and further, a concave portion 27d continuous with the groove 27b is formed.

In each of the above embodiments, a flow dividing plate is used as a flow dividing portion. However, the present invention is not limited to this. For example, a flow dividing member having an inclined surface, a plurality of branch flow paths, Etc. can also be adopted.

Hereinafter, the present invention will be described with reference to specific examples and comparative examples. In addition, the yarn breakage rate (times / t) measured in the following Examples and Comparative Examples is the number of yarn breaks per ton of spun fiber.

(Example 1) The discharge surface diameter of the nosol pack was 7
The spinning nozzle pack shown in FIG. 1, which employs a diverting plate having a diameter of 0 mmφ, a diameter of the constriction unit of 20 mmφ, a diverting slit having a slit width of 4 mm, and a slit depth of 8 mm, was mounted in a spinning cylinder of a dry spinning apparatus. The spinning of the acetate fiber yarn was performed. The spinning conditions were a dry hot air temperature of 80 ° C. and a spinning dope temperature of 60 ° C. when introduced into the spinning nozzle pack. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central part X and the peripheral part Y of the nozzle pack,
The temperature difference between the two was 1 ° C. or less. Furthermore, 100 fibers are arbitrarily extracted from the obtained fiber yarns, and the fineness of each single fiber is measured, and the CV indicating the variation in fineness is measured.
When the value was determined, the CV value was 2.87, and the variation was extremely small. Further, the yarn breakage rate in the spinning step was extremely low at 0.9 times / t.

(Embodiment 2) The discharge surface diameter of the nozzle pack is 8
The spinning nozzle pack shown in FIG. 1 employing a diversion plate having a diameter of 5 mm, a diameter of the constriction part of 20 mmφ, a diversion slit having a slit width of 4 mm, and a slit depth of 8 mm was used.
The cellulose acetate fiber yarn was spun under the same conditions as in Example 1. The temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central portion X and the peripheral portion Y of the nozzle pack, and the temperature difference between the two was 1 ° C. or less. Further, 100 fibers were arbitrarily extracted from the obtained fiber yarns, and the fineness of each single fiber was measured.
The V value was 2.94, and the variation was extremely small. Further, the yarn breakage rate in the spinning process is 1.0.
Times / t, which was extremely small.

(Embodiment 3) The discharge surface diameter of the nozzle pack is 1
The spinning nozzle pack shown in FIG. 1 employing a diversion plate having a diameter of 10 mmφ, a diameter of the constriction unit of 20 mmφ, a diversion slit having a slit width of 4 mm, and a slit depth of 8 mm was used under the same conditions as in Example 1. The cellulose acetate fiber yarn was spun. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central portion X and the peripheral portion Y of the nozzle pack, the temperature difference between them was 2 ° C. or less. Further, 100 fibers were arbitrarily extracted from the obtained fiber yarns, and the fineness of each single fiber was measured. The CV value indicating the variation in the fineness was 3.00, and the variation was small. there were. Further, the yarn breakage rate in the spinning step was as low as 1.1 times / t, and there was no problem.

(Embodiment 4) The discharge surface diameter of the nozzle pack is 1
The spinning nozzle pack shown in FIG. 1 employing a diversion plate with a diameter of 10 mmφ, a diameter of the drawing portion of 5 mmφ, a diversion slit having a slit width of 4 mm, and a slit depth of 8 mm,
The cellulose acetate fiber yarn was spun under the same conditions as in Example 1. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central portion X and the peripheral portion Y of the nozzle pack, the temperature difference between them was 2 ° C. or less. In addition, 100 fibers were arbitrarily extracted from the obtained fiber yarns, and the fineness of each single fiber was measured.
The V value was 2.88, and the variation was extremely small. In addition, the yarn breakage rate in the spinning process is 0.8.
Times / t, which was extremely small.

(Embodiment 5) The discharge surface diameter of the nozzle pack is 1
10mmφ, aperture diameter is 20mmφ, slit width of diversion slit is 4mm, slit depth is 15mm
The cellulose acetate fiber yarn was spun under the same conditions as in Example 1 using the spinning nozzle pack shown in FIG. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central portion X and the peripheral portion Y of the nozzle pack, the temperature difference between them was 2 ° C. or less. In addition, 100 fibers among the obtained fiber yarns were arbitrarily extracted, and the fineness of each single fiber was measured. The CV value indicating the variation in the fineness was 2.88, and the variation was extremely small. Met. In addition, the yarn breakage rate in the spinning step was extremely low at 0.7 times / t.

(Embodiment 6) The discharge surface diameter of the nozzle pack is 1
10mmφ, aperture diameter is 20mmφ, diversion slit slit width is 4mm, slit depth is 25mm
The cellulose acetate fiber yarn was spun under the same conditions as in Example 1 using the spinning nozzle pack shown in FIG. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central portion X and the peripheral portion Y of the nozzle pack, the temperature difference between them was 2 ° C. or less. In addition, 100 fibers of the obtained fiber yarns were arbitrarily extracted and the fineness of each single fiber was measured. The CV value indicating the variation in the fineness was 2.78, and the variation was extremely small. Met. Further, the yarn breakage rate in the spinning step was extremely low at 0.6 times / t.

(Embodiment 7) The discharge surface diameter of the nozzle pack is 1
10 mmφ, aperture diameter is 20 mmφ, diversion slit slit width is 4 mm, slit depth is 50 mm
The cellulose acetate fiber yarn was spun under the same conditions as in Example 1 using the spinning nozzle pack shown in FIG. The temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central portion X and the peripheral portion Y of the nozzle pack, and the temperature difference between the two was 1 ° C. or less. In addition, 100 fibers among the obtained fiber yarns were arbitrarily extracted and the fineness of each single fiber was measured. The CV value indicating the variation in the fineness was 2.65, and the variation was extremely small. Met. In addition, the yarn breakage rate in the spinning step was extremely low at 0.7 times / t.

(Embodiment 8) The discharge surface diameter of the nozzle pack is 1
10 mmφ, aperture diameter is 20 mmφ, diversion slit slit width is 4 mm, slit depth is 100 m
A cellulose acetate fiber yarn was spun under the same conditions as in Example 1 using the spinning nozzle pack shown in FIG. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central part X and the peripheral part Y of the nozzle pack,
The temperature difference between the two was 3 ° C. or less. In addition, 100 fibers were arbitrarily extracted from the obtained fiber yarns, and the fineness of each single fiber was measured. The CV value indicating the variation in the fineness was 3.01, and the variation was small. there were. In addition, the yarn breakage rate in the spinning process is 0.9.
Times / t.

(Embodiment 9) The discharge surface diameter of the nozzle pack is 1
The spinning nozzle pack shown in FIG. 1 employing a diverting plate having a diameter of 10 mmφ, a diameter of the constriction portion of 20 mmφ, a diverting slit having a slit width of 8 mm, and a slit depth of 8 mm was used under the same conditions as in Example 1. The cellulose acetate fiber yarn was spun. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central portion X and the peripheral portion Y of the nozzle pack, the temperature difference between them was 3 ° C. or less. In addition, 100 fibers were arbitrarily extracted from the obtained fiber yarns, and the fineness of each single fiber was measured. The CV value indicating the variation in the fineness was 3.31, and the variation was small. there were. Also, the yarn breakage rate in the spinning step was as low as 1.0 times / t.

COMPARATIVE EXAMPLE 1 A conventional nozzle pack 30 shown in FIG. 4 has a cylindrical pack peripheral wall 31a and a pack upper wall which closes the upper part of the pack peripheral wall 31a and has a central hole 31c for introducing a spinning solution. The pack body 31 includes a pack body 31. A packing 38 is provided at a joint between the pack peripheral wall 31a and the pack upper wall 31b. A spinneret 33 having a plurality of spinning holes is provided via a packing 39 at a discharge portion 31 d at the lower end of the pack body 31. Inside the pack body 31, a filter support porous plate 35 is provided.
And a filter 36 is placed on the upper surface of the perforated plate 35.

A conventional nozzle pack having the above configuration and having a discharge surface diameter of the nozzle pack of 70 mmφ as shown in FIG. 4 was mounted in a spinning cylinder of a dry spinning apparatus, and cellulose acetate was produced under the same spinning conditions as in Example 1. The fiber yarn was spun. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the center and the peripheral portion of the nozzle pack, the temperature difference between the two was extremely large, 8 ° C. When 100 fibers were arbitrarily extracted from the obtained fiber yarns and the fineness of each single fiber was measured, the CV value indicating the variation in the fineness was as large as 5.53, and the yarn in the spinning process was large. The breakage rate was 1.3 times / t, and the breakage occurred frequently, and the production efficiency was reduced.

(Comparative Example 2) The discharge surface diameter of the nozzle pack is 8
A conventional nozzle pack having a diameter of 5 mm as shown in FIG. 4 was mounted in a spinning cylinder of a dry spinning apparatus, and cellulose acetate fiber yarn was spun under the same spinning conditions as in Example 1. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the center and the peripheral portion of the nozzle pack, the temperature difference between the two was an extremely large temperature difference of 10 ° C. When 100 fibers were arbitrarily extracted from the obtained fiber yarns and the fineness of each single fiber was measured, the CV value indicating the variation in the fineness was as large as 5.69. The breaking rate was 1.8 times / t, which was extremely frequent, and the production efficiency was significantly reduced.

(Comparative Example 3) The discharge surface diameter of the nozzle pack is 1
A conventional nozzle pack having a diameter of 10 mm as shown in FIG. 4 was mounted in a spinning cylinder of a dry spinning apparatus, and cellulose acetate fiber yarn was spun under the same spinning conditions as in Example 1. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the center and the peripheral portion of the nozzle pack, the temperature difference between the two was an extremely large temperature difference of 12 ° C. In addition, 100 fibers were arbitrarily extracted from the obtained fiber yarns, and the fineness of each single fiber was measured.
The value was as large as 5.86, and the yarn breakage rate in the spinning step was 2.1 times / t, which was extremely frequent, and the production efficiency was significantly reduced.

(Comparative Example 4) The discharge surface diameter of the nozzle pack is 1
The spinning nozzle pack shown in FIG. 1 employing a diverting plate having a diameter of 10 mmφ, a diameter of the drawing portion of 50 mmφ, a diverting slit having a slit width of 4 mm, and a slit depth of 8 mm was used under the same conditions as in Example 1. The cellulose acetate fiber yarn was spun. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central portion X and the peripheral portion Y of the nozzle pack, a large temperature difference of 6 ° C. was observed between the two. This is because the spinning stock solution was not sufficiently kneaded due to the large diameter of the drawing portion. In addition, 100 fibers were arbitrarily extracted from the obtained fiber yarns, and the fineness of each single fiber was measured.
The value was 4.89, and the variation was so large that it could not be ignored. Further, the yarn breakage rate in the spinning step was as large as 1.8 times / t, and the production efficiency was reduced.

(Comparative Example 5) The discharge surface diameter of the nozzle pack is 1
10mmφ, aperture diameter is 20mmφ, split slit width is 12mm, slit depth is 8mm
The cellulose acetate fiber yarn was spun under the same conditions as in Example 1 using the spinning nozzle pack shown in FIG. When the temperature of the spinning solution in the nozzle pack immediately before being discharged from the spinneret was measured at the central portion X and the peripheral portion Y of the nozzle pack, a large temperature difference of 8 ° C. was observed between the two. This is because the slit width of the branch slit is large, so that the spinning dope is heated unevenly when passing through the slit, and the kneading of the spinning dope becomes insufficient. Also,
When 100 fibers were arbitrarily extracted from the obtained fiber yarns and the fineness of each single fiber was measured, the CV value indicating the variation in the fineness was 4.56, and the variation was large and could not be ignored. there were. In addition, the yarn breakage rate in the spinning step was as high as 1.5 times / t.

[0048]

As described above, according to the present invention, the undiluted spinning solution in the spinning nozzle pack can be brought to a uniform temperature near the peripheral wall and at the center of the nozzle pack. Because the viscosity unevenness of the stock solution can be effectively suppressed,
It is possible to produce a fiber yarn with less fineness unevenness between single yarns. In addition, by suppressing such unevenness in fineness, the generation of fibers having low strength is suppressed, yarn breakage in the spinning process is significantly reduced, spinning stability is also extremely good, and efficient production of fiber yarns is possible. Become.

[0049]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing a dry spinning nozzle pack according to a preferred embodiment of the present invention.

FIG. 2 is a top view and a side view of a flow dividing plate applicable to the nozzle pack.

FIG. 3 is a top view and a side view of another flow dividing plate applicable to the nozzle pack.

FIG. 4 is a sectional view schematically showing a conventional spinning nozzle pack.

DESCRIPTION OF SYMBOLS 10 Nozzle pack 11 Pack main body 11a Pack peripheral wall 11b Pack upper wall 11c Introducing hole of spinning solution 11d Discharge part 12 Bolt 13 Spinneret 14 Partition plate 14a Through hole (throttle part) 15 Perforated plate 16 Filtration body 17 Branch flow Plate 17a Ridge 17b Dividing slit 17c Dividing concave portion 27 Dividing plate 27b Groove (dividing slit) 27c Dividing concave portion 27d Depressed portion 30 Nozzle pack 31 Pack main body 31a Pack peripheral wall 31b Pack upper wall 31c Spinning stock solution introduction hole 31d discharge section 33 spinning Cap 35 Filtration body support porous plate 36 Filtration body 38 Packing 39 Packing W Slit width D Slit depth L Discharge surface diameter

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hironari Inada 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Central Research Laboratory F-term (reference) 4L035 AA07 BB02 DD20 4L045 AA01 BA03 BA60 CA25 CA32 CA40 CB09 DA36

Claims (9)

[Claims] 1. A spinning nozzle pack having an introduction section and a discharge section for a spinning dope, wherein a splitting section for splitting a plurality of spinning dope introduced from the introduction section into the nozzle pack. A spinning unit for re-merging the spinning solution. 2. The diversion section includes a diversion plate arranged across the flow of the spinning dope, and a plurality of diversion slits are formed between a peripheral edge of the diversion plate and an inner peripheral wall of the nozzle pack. The spinning nozzle pack according to claim 1, wherein 3. The slit width of the split slit is 0.1.
The nozzle pack for spinning according to claim 2, which has a diameter of from about 8 mm. 4. A slit depth of the split slit is 4 to 4.
The spinning nozzle pack according to claim 2 or 3, which is 100 mm. 5. The flow dividing plate according to claim 2, further comprising a plurality of diversion recesses arranged radially from the center to the periphery on the upstream surface thereof and communicating with the diversion slit. A spinning nozzle pack according to any of the claims. 6. The throttle portion has a diameter of 2 to 40 mmφ.
The nozzle pack for spinning according to any one of claims 1 to 5, wherein 7. The spinning apparatus according to claim 1, wherein a filter of a stock solution for spinning is further disposed inside the nozzle pack, and a spinneret having a plurality of spinning holes is disposed at the discharge section. Nozzle pack. 8. The discharge section has a discharge surface diameter of 20 to 200 m.
The nozzle pack for spinning according to any one of claims 1 to 7, which has a diameter of mφ. 9. A method for producing cellulose acetate fiber yarn by dry spinning, comprising using the nozzle pack for spinning according to any one of claims 1 to 8, wherein the cellulose acetate fiber yarn is used. Manufacturing method.