JP5428979B2 - Spin pack and method for producing filament yarn - Google Patents

Description

  The present invention relates to a spinning pack and a method for producing a filament yarn.

  Filament yarns composed of polyester and polyamide, such as polyester fiber and nylon fiber, are generally equipped with a spinning method, that is, a thermoplastic polymer such as polyester or polyamide is melted and supplied to a spinning pack. After spinning from the spinneret as a filament yarn, cooling and solidifying with an air flow, etc., if necessary, bundling or applying an oil agent, etc., once taken up with a roller, etc. Etc. are manufactured through a process such as winding. The above-described drawing, heat treatment, and the like are performed when the filament yarn spun from the spinneret is cooled and solidified by an air current or the like and then passed through a heating tube or the like. It may be performed in a process.

  On the other hand, filament yarn composed of acrylic fiber, polyacrylonitrile, etc. is generally equipped with a spinning pack, that is, a polymer such as polyacrylonitrile is dissolved in a solvent and supplied to a spinning pack as a polymer solution. After being spun into a coagulation bath as a filament yarn from a spinneret and solidified, it is manufactured through a process such as washing, drawing, drying, or applying an oil as necessary, and then winding. As described above, the filament yarn is spun into a coagulation bath from the spinneret and solidified, as described above, the filament yarn is directly spun into the coagulation bath and solidified, and the filament yarn from the spinneret is solidified. A method of spinning in a gas and then solidifying by passing through a coagulation bath is known. Generally, the former is called a wet spinning method and the latter is called a dry wet spinning method.

  In the solution spinning method, a polymer is dissolved in a volatile solvent, supplied to a spinning pack as a polymer solution, spun into a heated gas as a filament yarn from a spinneret equipped in the spinning pack, and the solvent is evaporated. There is also a method of producing a filament yarn after being solidified by such a method, once taken up by a roller or the like, subjected to drawing or the like as necessary, and then taken up. This method is generally called a dry spinning method, and this method is adopted for polyurethane fibers and the like.

  In the present specification, hereinafter, the molten polymer used in the melt spinning method and the polymer solution dissolved in the polymer solvent used in the solution spinning method will be collectively referred to as a polymer.

  Here, the spinning pack adopted by each spinning method is mainly composed of a filter layer, a perforated plate, and a spinneret. The melted polymer is filtered through the filter layer, and the spinneret is then perforated by the perforated plate. It is aimed to accurately weigh and discharge with a spinneret after being guided to the end, and it is generally recognized as an extremely important device for producing filament yarn stably, and various developments have been made so far. Has been made. For example, in the field of the melt spinning method, with the aim of improving productivity, many developments such as speeding up and forming multiple yarns by spinning a plurality of filament yarns from a single spinneret have been carried out.

  On the other hand, in recent years, the needs for filament yarn have diversified, and many special filament yarns with various functions have been developed and put on the market. For example, in the field of clothing, the single yarn has an irregular cross section for the purpose of giving fine texture, soft filaments, etc., and improving the water absorption and quick drying, and changing the glossiness. Improvements such as modifying polymers with the aim of imparting new functionality such as realization of dyeing with excellent sharpness have been made. Similarly, in the industrial field, in addition to making single yarn finer, multifilament, and single yarn irregular cross-section, new functionalities such as high strength, high elasticity, weather resistance, flame resistance, etc. Improvements such as targeted polymer modification have been made. Furthermore, recently, attempts to provide a combination of a plurality of functionalities as described above have begun actively.

  However, special filament yarns as described above are high-functional varieties having excellent functionality, but also difficult-to-spin varieties. Therefore, it is extremely difficult to produce special filament yarns with high productivity, specifically, at high speed, multiple yarns, or high speed and multiple yarns, and the special filament yarns are low in cost. As a result, it has been a hindrance to the expansion of sales and applications of special filament yarns.

  This problem will be described by taking as an example the case where the filament yarn is made into a single yarn fineness and multifilament in the field of melt spinning. According to the knowledge of the present inventors, generally, when the fineness of single yarn is reduced, the flow rate of the polymer passing through the spinning pack decreases, so that the residence time of the polymer becomes long and the melt viscosity tends to increase. Become. As a result, melt viscosity variation due to the residence time difference occurred in the spinning pack, the polymer flow became unstable, and led to large fineness spots between the filament yarns spun from the spinneret. In addition, when the number of filaments is increased in accordance with the above, fineness irregularities between single yarns increase as the number of filaments increases, which is a serious problem. In addition, abnormal stagnation is likely to occur as the melt viscosity increases, and thread breakage frequently occurs during spinning, resulting in a problem of deterioration in operability.

  This problem also becomes a serious problem with filament yarns made of modified polymers. According to the knowledge of the present inventors, for example, in a thermoplastic polymer, as an example of a method for modifying the polymer, copolymerization can be mentioned. Generally, when copolymerization is performed, the molecular structure is disturbed. Yarn strength and elongation tend to be low. Therefore, in many cases, measures to increase the melt viscosity of the polymer can be taken.However, in this case, in the spinning pack, the polymer is highly sensitive to the residence time of the polymer, and the melt viscosity increases with a slight increase in the residence time. Too much polymer flow instability was induced, leading to large fineness spots between the filament yarns spun from the spinneret. In addition, according to the knowledge of the present inventors, some thermoplastic polymers are more dependent on residence time and tend to increase the melt viscosity than polyesters and polyamides that are widely used in general. In the filament yarn composed of such a special polymer, the influence on the fineness spot becomes more remarkable. In the same manner as described above, abnormal stagnation occurred as the melt viscosity increased, and the operability deteriorated due to frequent yarn breakage. Furthermore, when a plurality of the above-described functionalities are combined, for example, when a combination of fineness of single yarn / multifilament and modification of polymer are combined, these problems become even more serious problems.

  As mentioned above, as means for improving productivity, means such as high speed and multiple yarns can be mentioned. For example, in the field of melt spinning, the function of the filament yarn that can be produced when speed is increased. It is known that the width of the sex variation tends to be narrow. In addition, in recent years, in the field of melt spinning, there has been an increasing need to reduce the fineness of the filament yarn itself as a filament yarn for high-density fabrics, etc., and the production of filament yarn from a single spinneret has been maintained. On the other hand, it is considered that the importance of making multiple yarns capable of simultaneously producing a plurality of special filament yarns will increase further in the future.

  As described above, the special filament yarn as described above is produced with high productivity, in particular, when it is manufactured with multiple yarns, by preventing abnormal retention in the spinning pack and suppressing the residence time, It is a very important technical problem to suppress fineness unevenness between the filament yarns spun from, and various proposals have been made conventionally.

  For example, Patent Document 1 discloses a spinning pack as shown in FIG. FIG. 8 is a schematic cross-sectional view of the spinning pack of Patent Document 1. In the figure, 1 is an upper lid, 2 is a distribution plate, 3 is a filter layer, 4 is a perforated plate, 5 is a spinneret, 6 is a spinning pack body, 8 is a central flow path, 9 is a central enlarged flow path, and 10 is an outer peripheral upper surface. A flow path, 11 is an outer peripheral lower surface flow path, 12 is an outer peripheral flow path, 13 is a distribution hole, 17 is a polymer inflow hole. Hereinafter, in each drawing, when a member corresponding to the already-explained drawing exists, the description may be omitted by using the same reference numerals. In Patent Document 1, a distribution plate 2 is provided in a widened flow path from a polymer inlet hole 17 having a small inlet diameter to a filter layer 3 having a large inlet diameter, and the polymer passing through the center of the spinning pack is a central flow path. 8. When the polymer that is guided to the central enlarged flow path 9 and passes through the outer periphery is guided to the outer peripheral upper surface flow path 10, the outer peripheral flow path 12, and the outer peripheral lower surface flow path 11, it is possible to prevent abnormal retention in the outer peripheral region. Have been described. Further, it is described that the polymer can be sufficiently distributed to the outer periphery by setting the cross-sectional area of the central flow path 8 to 1/20 to 1/100 of the total polymer passage cross-sectional area. In addition, it is described that the provision of the central enlarged flow path 9 can suppress abnormal stagnation between the central enlarged flow path 9 and the outer peripheral flow path 12.

  Further, as a structure similar to Patent Document 1, a spin pack as shown in FIG. 9 is disclosed. FIG. 9 is a schematic cross-sectional view of the spin pack of Patent Document 2. In the figure, 14 is an introduction hole. Patent Document 2 uses the distribution plate 2 to suppress the residence time difference between the polymer passing through the central flow path 8 and the outer peripheral flow path 12 and reduce the thermal history difference of the polymer. It is described that it becomes uniform and, as a result, fineness unevenness between single yarns and / or yarns can be suppressed.

  Patent Document 3 discloses a spinning pack as shown in FIG. FIG. 10 is a schematic cross-sectional view of the spin pack of Patent Document 3. In Patent Document 3, the upstream opening of the distribution hole 13 of the porous plate 4 is divided into the central side and the outer peripheral side of the porous plate 4, and the central distribution hole 13 and the outer peripheral distribution hole 13 are arranged downstream. It is described that the polymer flow rate difference and the thermal history difference on the center side and the outer peripheral side are different by mixing, the polymers having a polymerization degree and a melt viscosity difference are mixed and uniformly dispersed, and as a result, fineness spots can be suppressed. Has been.

  Further, as similar to Patent Document 3 and related to a perforated plate, Patent Document 4 discloses a spinning pack as shown in FIG. FIG. 11 is a schematic cross-sectional view of the spin pack of Patent Document 4. In the figure, 18 indicates a mixing block. In Patent Document 4, a mixing block 18 is disposed between the perforated plate 4 and the spinneret 5. The mixing block 18 includes a plurality of cylindrical diameter channels provided on a single circumference. Yes. Therefore, the difference between the inner and outer layers is eliminated by mixing the non-uniform polymer having a difference in melt viscosity between the central side and the outer peripheral side of the spinning pack in the cylindrical diameter flow path of the mixing block 18, thereby reducing the yarn breakage. It is stated that you can.

JP-A-7-305216 JP 2006-37286 A JP-A-9-268418 JP 2008-38278 A

However, the conventional spinning pack has the following problems.
Patent Document 1 (see FIG. 8) pays attention to suppression of abnormal stagnation of the distribution plate 2 and does not take into account the residence time itself on the downstream side of the distribution plate 2. This is because, even if abnormal retention is suppressed in the distribution plate 2, if dispersion in residence time occurs in the filter layer 3, the perforated plate 4, and the spinneret 5 located on the downstream side, dispersion in melt viscosity will occur. And this may lead to fineness spots. In particular, since the porous plate 4 is provided with a large number of small diameter holes on one side, the residence time increases due to the expansion of the flow path space, and the dispersion of the residence time may increase. Further, according to the knowledge of the present inventors, since the outer edge portion of the distribution plate 2 is fixed between the upper lid 1 and the porous plate 4, the outer peripheral lower surface flow path 11 is provided by the amount of the outer edge portion. There is a problem that the passage space is enlarged and the residence time is increased.

  Patent Document 2 (see FIG. 9) focuses on reducing the difference in residence time of the polymer flowing into the filter layer 3 from the center side and side surface side of the distribution plate 2, and the residence time itself downstream from the filter layer 3 itself. Is not considered. This is because even if the residence time difference of the polymer flowing into the filter layer 3 is reduced, the cross-sectional area is small on the center side of the filter layer 3, so that the polymer flow rate is fast, and conversely, the cross-sectional area is large on the side surface side. As a result, the flow rate is slow, and as a result, a residence time difference occurs in the filter layer 3, but the specification of this document does not specify any means for reducing the residence time difference downstream of the filter layer 3. Further, a flow path for guiding the polymer to the spinneret 5 having a large number of introduction holes 14 is not provided downstream of the filter layer 3, and the polymer flowing out from the filter layer 3 is directly introduced into the introduction holes of the spinneret 5. 14 leads to. For this reason, the dispersion of the residence time greatly depends on the arrangement of the introduction holes 14. For example, in the case where the introduction holes 14 are arranged in a staggered manner on the entire surface of the base, they are generated in the filter layer 3 described above. The residence time difference may further increase.

  In Patent Document 3 (see FIG. 10), in the widened flow path from the polymer inlet hole 17 having a small inlet diameter to the filter layer 3 having a large inlet diameter, the space becomes extremely large, so that the residence time increases. In addition, a difference in the residence time of the polymer passing through the central side and the outer peripheral side is unavoidable. Therefore, in the perforated plate 4, it may not be possible to uniformly disperse by simply mixing the polymer on the center side and the outer periphery side. In particular, mixing a polymer having an excessive residence time difference, that is, a polymer having an excessive melt viscosity difference, on the downstream side of the filter layer 3 that further widens the residence time difference, on the contrary, leads to instability of the polymer flow. There is.

  In Patent Document 4 (see FIG. 11), as in Patent Document 3, the passage space from the polymer inflow hole 17 to the filter layer 3 becomes extremely large, so that the residence time increases, and the center side and the outer periphery side are also increased. The difference in the residence time of the polymer passing through the filter is generated, and the difference between the inner and outer layers cannot be eliminated only by the mixing block 18 (the role of the perforated plate of Patent Document 3). As a result, the polymer flow may become unstable. Further, an unnecessary space is formed between the mixing block 18 and the porous plate 4, the residence time difference is enlarged in the inner and outer layers, and the hole arrangement of the porous plate 4 is, for example, staggered as described in the specification In the case of the arrangement, the residence time difference in the inner and outer layers may increase. Further, the outlet of the cylindrical diameter channel disposed in the mixing block 18 does not match the inlet to the introduction hole 14 of the spinneret 5, and further, unnecessary between the mixing block 8 and the spinneret 5. Since there is a large space, a stagnant portion may occur particularly in the center and the outer periphery.

  As described above, by preventing abnormal retention in the spinning pack and suppressing the residence time, suppressing fineness unevenness between the filament yarns spun from the spinneret can improve the productivity of filament yarn production. Although it is a very important element in the above, as mentioned above, various problems remain and hinder the improvement of the productivity of filament yarn production. Therefore, solving the problems related to the suppression of fineness spots has an important industrial significance.

  Therefore, the object of the present invention is to cope with various polymer types and varieties, no yarn breakage, etc., excellent spinning stability, small fineness unevenness between single yarns, between yarns, An object of the present invention is to provide a spinning pack and a method for producing a filament yarn that exhibit remarkable effects in order to obtain a yarn having good quality such as strength and elongation.

In order to achieve the above object, a spin pack of the present invention has the following configuration. That is, the present invention is a spinning pack for spinning a thermoplastic polymer as a filament yarn,
An upper lid formed with a polymer inflow hole and a lower surface that extends from the downstream opening of the polymer inflow hole toward the outer peripheral side and the downstream side;
Arranged on the downstream side of the upper lid, a central flow path, an outer peripheral upper surface extending from the upstream opening of the central flow path toward the outer peripheral side and the downstream side, and an outer periphery narrowing from the outer peripheral edge toward the central side and the downstream side A distribution plate formed with a lower surface and a central enlarged lower surface that extends from the downstream opening of the central flow path toward the outer peripheral side and the downstream side and is connected to the outer peripheral lower surface;
A filtration unit disposed downstream of the distribution plate;
A perforated plate that is arranged on the downstream side of the filtration unit and has a plurality of distribution holes arranged in a circumferential shape from the upper surface to the lower surface, and
A spinneret formed on the downstream side of the perforated plate and formed with introduction holes arranged circumferentially from the upper surface to the downstream side, and discharge holes communicating with the introduction holes and discharging thermoplastic polymer from the lower surface When,
Is stored in a cylindrical spinning pack body,
The distribution plate is disposed at a distance from the lower surface of the upper lid and the inner wall surface of the spin pack body, and an outer peripheral upper surface flow path is formed between the outer peripheral upper surface of the distribution plate and the lower surface of the upper lid. An outer peripheral lower surface flow path is formed between the outer peripheral lower surface of the plate and the filtration part, and the outer peripheral upper surface flow path and the outer peripheral lower surface flow path are a gap between the distribution plate and the inner wall surface of the spinning pack body. A central enlarged flow path communicating with the central flow path is formed between the central enlarged lower surface of the distribution plate and the filtration portion;
The pitch circle diameter of the distribution holes on the upper surface of the perforated plate is 85 to 105% of the maximum diameter of the central enlarged lower surface of the distribution plate.

  The method for producing a filament yarn of the present invention is a method for producing a filament yarn in which the spinning pack of the present invention is used to spin a thermoplastic polymer as a filament yarn.

  In the present invention, the “flow direction of the thermoplastic polymer” is the main direction in which the thermoplastic polymer flows from the polymer inflow hole of the upper lid to the spinneret, and refers to the axial direction of the cylindrical spinning pack body.

  In the present invention, the “upstream side” refers to the direction upstream of the flow path of the thermoplastic polymer, and the “downstream side” refers to the direction downstream of the flow path of the thermoplastic polymer.

  In the present invention, the “upper surface” is the upstream surface of each member in the state of being accommodated in the spin pack, and the “lower surface” is the downstream side of each member in the state of being accommodated in the spin pack. It is a surface.

  In the present invention, the “maximum diameter of the central enlarged lower surface of the distribution plate” refers to the diameter of a circumferential boundary line where the outer peripheral lower surface of the distribution plate and the central enlarged lower surface intersect. Hereinafter, this diameter is referred to as a maximum diameter (DMAX).

  In the present invention, the “pitch circle diameter” is a diameter of a circle formed by connecting a plurality of circles in a circle and connecting the centers of the circles, and is usually abbreviated as PCD (Pitch Circle Diameter). The

  In the present invention, the “pitch circle diameter of the distribution holes on the upper surface of the porous plate” is the diameter of a circle formed by connecting the centers of a plurality of distribution holes arranged circumferentially on the upper surface of the porous plate. If the holes are arranged in a single row, the pitch circle diameter is used. If the distribution holes are arranged in a plurality of rows, the outermost pitch circle diameter is used. Hereinafter, this diameter is referred to as a pitch circle diameter (SUP).

  In the present invention, “the pitch circle diameter of the distribution holes on the lower surface of the perforated plate” means the diameter of a circle formed by connecting the centers of a plurality of distribution holes arranged in a row on the lower surface of the perforated plate. say. Hereinafter, this diameter is referred to as a pitch circle diameter (SLP).

  In the present invention, “the pitch circle diameter of the introduction holes on the upper surface of the spinneret” is the diameter of a circle formed by connecting the centers of a plurality of introduction holes arranged circumferentially on the upper surface of the spinneret. If the holes are arranged in a single row, the pitch circle diameter, and if the introduction holes are arranged in a plurality of rows, the innermost pitch circle diameter and the outermost pitch circle diameter. The diameter of the virtual circle that is the average value. Hereinafter, this diameter is referred to as a pitch circle diameter (DUP).

  According to the spinning pack and multifilament yarn manufacturing method of the present invention, it can be used for various polymer types and varieties, has no yarn breakage, has excellent spinning stability, and has fineness irregularities between single yarns and yarns. It is possible to obtain a yarn having a small size and a good quality such as a thickness variation of the yarn and strength and elongation.

It is a schematic sectional drawing of the spin pack used for embodiment of this invention. It is an enlarged view of the upper cover and distribution plate of a spinning pack used in an embodiment of the present invention. It is a schematic sectional drawing of the spin pack used for another embodiment of this invention. It is a schematic sectional drawing of the spin pack used for another embodiment of this invention. It is a schematic sectional drawing of the spin pack used for another embodiment of this invention. It is a schematic sectional drawing of the spinning pack used for embodiment of this invention, and a cooling device periphery. It shows the relationship between the residence time of the spin pack used in the embodiment of the present invention and the spin pack of the conventional example and the flow rate ratio passing through the spin pack. It is a schematic sectional drawing of the spinning pack of a prior art example. It is a schematic sectional drawing of the spinning pack of a prior art example. It is a schematic sectional drawing of the spinning pack of a prior art example. It is a schematic sectional drawing of the spinning pack of a prior art example.

Hereinafter, embodiments of the spin pack of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of a spin pack used in an embodiment of the present invention, and FIGS. 3, 4, and 5 are schematic cross-sectional views of a spin pack used in another embodiment of the present invention. FIG. 6 is a schematic cross-sectional view around a spinning pack and a cooling device used in the embodiment of the present invention. Note that these are conceptual diagrams for accurately transmitting the main points of the present invention, the drawings are simplified, the spinning pack of the present invention is not particularly limited, and the dimensional ratio is in accordance with the embodiment. It can be changed.

  As shown in FIG. 6, the spin pack 7 used in the embodiment of the present invention is mounted on the spin pack body 6, fixed in the spin block 19, and a cooling device 20 is configured immediately below the spin pack 7. . Therefore, the polymer guided to the spin pack 7 is discharged from the discharge hole 15 of the spinneret 5 through the distribution plate 2, the filter layer 3, the filter 16, the perforated plate 4, and the spinneret 5, and then is cooled by the cooling device 20. After being cooled by the air flow blown and oiled, it is wound up as a multifilament yarn. In addition, in FIG. 6, although the cyclic | annular cooling device 20 which blows off airflow in cyclic | annular inward is employ | adopted, you may use the cooling device which blows off airflow from one direction. In FIG. 6, a configuration is adopted in which steam is applied by the steam applying device 21 and the lower surface of the spinneret 5 is sealed. In addition, as for the member to be installed on the upstream side of the spinning pack 7, an existing member or the like may be used, and it is not necessary to dedicate specially.

  As shown in FIG. 1, the spin pack 7 used in the embodiment of the present invention has an upper lid 1, a distribution plate 2, a filtration unit 22, in the cylindrical spin pack body 6 in order from the upstream side to the downstream side. A perforated plate 4 and a spinneret 5 are arranged. FIG. 2 is an enlarged view in which only the upper lid 1 and the distribution plate 2 are extracted.

  In the upper lid 1 of the present invention, a cylindrical polymer inflow hole 17 in which a polymer flows is formed in the center. The lower surface 23 of the upper lid 1 has a shape that expands from the downstream opening of the polymer inflow hole 17 toward the outer peripheral side and the downstream side.

The distribution plate 2 according to the present invention is disposed at a distance from the lower surface 23 of the upper lid 1 and the inner wall surface of the spinning pack body 6 . In the center of the distribution plate 2, a cylindrical central flow path 8 through which a polymer flows is formed. The upper surface of the distribution plate 2 has a shape that expands from the upstream opening of the central flow path 8 toward the outer peripheral side and the downstream side. In the present invention, this upper surface is referred to as the outer peripheral upper surface 24. The outer peripheral side of the lower surface of the distribution plate 2 has a shape that narrows from the outer peripheral edge toward the central side and the downstream side. In the present invention, the lower surface on the outer peripheral side is referred to as the outer peripheral lower surface 26. The central side of the lower surface of the distribution plate 2 has a shape that expands from the downstream opening of the central channel 8 toward the outer peripheral side and the downstream side. In the present invention, this lower surface on the central side is referred to as a central enlarged lower surface 27. . The outer peripheral lower surface 26 and the central enlarged lower surface 27 are connected, and the boundary line is a circumference. In FIG. 2, a belt-like outer peripheral surface 25 that connects the outer peripheral upper surface 24 and the outer peripheral lower surface 26 is formed. However, this outer peripheral surface 25 is not necessarily required, and the thickness of the distribution plate 2 is reduced to reduce the outer peripheral surface. 25 may be eliminated, and the outer peripheral upper surface 24 and the outer peripheral lower surface 26 may be directly connected.

  The distance between the outer peripheral upper surface 24 of the distribution plate 2 and the lower surface 23 of the upper lid 1, the distance between the outer peripheral lower surface 26 of the distribution plate 2 and the filtering portion 22, and the center enlarged lower surface 27 of the distribution plate 2 and the filtering portion 22. In the present invention, these channels are referred to as the outer peripheral upper surface flow channel 10, the outer peripheral lower surface flow channel 11, and the central enlarged flow channel 9, respectively. The polymer inflow hole 17 and the central flow path 8, the polymer inflow hole 17 and the outer peripheral upper surface flow path 10, and the central enlarged flow path 9 and the central flow path 8 communicate with each other so that the polymer flows. Further, the outer peripheral upper surface flow path 10 and the outer peripheral lower surface flow path 11 communicate with each other at an interval between the distribution plate 2 and the inner wall surface of the spinning pack body 6. In FIG. 1, there is an outer peripheral channel 12 between the belt-shaped outer peripheral surface of the distribution plate 2 and the inner wall surface of the spinning pack body 6, and the outer peripheral upper surface channel 10 and the outer peripheral lower surface channel 11 are the outer peripheral channel 12. It communicates through. The outer peripheral flow path 12 may be omitted, but the outer peripheral flow path 12 is preferable. When the outer peripheral flow path 12 is present, a section in which the flow path cross-sectional area is constant is formed, and the polymer flow can be once rectified. In addition, when the polymer moves from the outer peripheral upper surface flow path 10 to the outer peripheral lower surface flow path 11, it is possible to prevent the polymer flow direction from being bent (bent), and to prevent abnormal retention of the polymer. In addition, even if there is no belt-shaped outer peripheral surface 25, that is, the outer peripheral upper surface flow channel 10 and the outer peripheral lower surface flow channel 11 communicate with each other without passing through the outer peripheral flow channel 12, the distribution plate 2 and the inner wall surface of the spinning pack body 6 Is considered to communicate with each other.

  In FIG. 1, the lower surface 23 of the upper lid 1, the outer peripheral upper surface 24, the outer peripheral lower surface 26, and the central enlarged lower surface 27 of the distribution plate have a conical shape, that is, a cut surface is a straight line. If the flow of the polymer in each flow path is not hindered, the cut surface may have a curved shape. In this case, it is preferable that the flow path gap between the upper lid 1 and the distribution plate 2 is constant or the flow path gap is made smaller in the downstream direction.

  The distribution plate 2 may be fixed to the upper lid 1 via a spacer or may be fixed to the spinning pack body 6 so as to form a constant flow path gap with the upper lid 1. . In particular, when spacers are used, several types of spacers having different heights can be prepared, the spacers can be changed according to the type and spinning conditions, and the channel gap of the outer peripheral upper surface channel 10 can be adjusted. Furthermore, by using the spacer, the flow gap accuracy is improved, and as a result, the flow rate variation of the polymer can be reduced.

  The filtration unit 22 in the present invention has a role for removing foreign substances contained in the polymer. In FIG. 1, the filtration part 22 is comprised by the filter layer 3 and the filter 16, and supports the filter layer 3 comprised by the filter sand with the filter 16 of a metal mesh. However, if only the filter layer 3 has shape retention, the filter part 22 may be constituted only by the filter layer 3, or if the filter 16 can sufficiently remove foreign substances contained in the polymer, the filter The filtration part 22 may be comprised only by 16.

  The porous plate 4 according to the present invention has a plurality of distribution holes 13 that communicate from the upper surface to the lower surface and through which the polymer flows. The distribution holes 13 are arranged circumferentially on the upper and lower surfaces.

  The spinneret 5 in the present invention is formed with an introduction hole 14 that extends from the upper surface to the downstream side, and a discharge hole 15 that communicates with the introduction hole and reaches the lower surface. The polymer entering from the introduction hole 14 is discharged from the discharge hole 15.

  The perforated plate 4 and the spinneret 5 are positioned by a positioning pin so that the center positions (cores) of the distribution holes 13 and the introduction holes 14 arranged in a circle are aligned with each other, and after overlapping, screws, bolts, etc. It may be fixed with.

  What is characteristic in the present invention is that the pitch circle diameter of the distribution holes 13 on the upper surface of the porous plate 4 and the maximum diameter of the central enlarged lower surface 27 of the distribution plate 2 are substantially the same. Specifically, the pitch circle diameter of the distribution holes 13 on the upper surface of the porous plate 4 is 85 to 105% of the maximum diameter of the central enlarged lower surface of the distribution plate 2.

  First, by taking the above-described embodiment of the present invention, a polymer can be discharged from the discharge holes 15 of the spinneret 5 and fineness unevenness between single yarns and yarns of the wound multifilament yarn can be suppressed. The principle will be explained. As described in the prior art, the cause of the fineness unevenness includes an abnormal retention of the polymer in the spinning pack 7, an increase in the retention time of the polymer, and an increase in the variation in the retention time.

  In particular, as a necessary function of the spinning pack 7, a filtration unit 22 having a role of filtration is necessary to remove foreign substances contained in the polymer. The filtration part 22 increases the cross-sectional area in the direction perpendicular to the flow path direction of the thermoplastic polymer, thereby suppressing an increase in filtration pressure with time and allowing stable filtration. Therefore, the polymer inflow hole 17 of the spin pack 7 can be filtered. It is preferable that the flow path is once widened on the upstream side of the filtration unit 22 and the flow path is reduced again on the downstream side of the filtration unit 22 while reducing the cross-sectional area of the flow channel as much as possible. However, if this is done, the problem of increased polymer residence time and residence time variation in the widened portion and reduced portion of the flow path is unavoidable.

  It should be noted that the abnormal retention of the polymer is reduced by reducing unnecessary channel space in the spinning pack 7 as much as possible and optimizing the channel. Therefore, it is extremely important to suppress the remaining time and variation of the polymer, which is a remaining problem, and to suppress fineness unevenness between each single yarn and each yarn resulting therefrom.

  Here, FIG. 7 shows the relationship between the residence time of the spin pack 7 used in the embodiment of the present invention and the typical spin pack used in the prior art and the flow rate of the polymer passing through the spin pack. is there. The polymer passing through the spinning pack 7 flows in from the polymer inflow hole 17 and is discharged from the discharge hole 15, and among them, the polymer passing through the path having the minimum residence time begins to be discharged from the discharge hole 15, Next, the polymer that passes through the path having the peak discharge flow rate ratio and the maximum residence time is discharged from the discharge hole 15. In view of this, the average value of the residence time and the variation in residence time are the maximum value of the residence time, and it is most effective to reduce this. Therefore, the present inventors have investigated the path in which the maximum residence time occurs in the spin pack 7 and conducted intensive studies, so that no consideration has been given to the spin pack 7 in the conventional technology. The technology has been found to limit the residence time and dispersion of residence time to the maximum.

  As shown in FIG. 1, the spin pack 7 of the present invention is provided with a distribution plate in order to suppress an increase in the residence time of the polymer in the flow path widening portion on the upstream side in the flow path direction of the thermoplastic polymer of the filtration portion 22. 2 is disposed. Therefore, the polymer passing through the distribution plate 2 through the polymer inflow hole 17 flows into the polymer flowing in the central flow path 8 provided at the center and the outer peripheral upper surface flow path 10 sandwiched between the upper lid 1 and the distribution plate 2. Divided into polymers. The polymer that has passed through the central flow path 8 flows to the filtration unit 22 via the central enlarged flow path 9. Further, the polymer flowing in the outer peripheral upper surface flow path 10 flows into the filtration unit 22 through the outer peripheral flow path 12 and the outer peripheral lower surface flow path 11. Among the polymers flowing into the filtering unit 22, the path having the minimum residence time is the polymer inflow hole 17 → the central channel 8 → the central enlarged channel 9 → the filtering unit 22 (referred to as a path MIN). The path having the maximum residence time is polymer inflow hole 17 → outer peripheral upper surface flow path 10 → outer peripheral flow path 12 → outer peripheral lower surface flow path 11 → filter part 22 (referred to as path MAX). In particular, in the outer peripheral lower surface flow path 11, the residence time of the path flowing into the filtration unit 22 after going from the outer periphery to the center becomes the longest. Therefore, as shown in FIG. 7, the route having the minimum residence time is the route MIN, and the route having the maximum residence time is the route MAX. It is important to guide the nozzle to the discharge hole 15 of the spinneret 5 through the path having the shortest residence time.

  Therefore, in the spinning pack 7 of the present invention, the maximum diameter (DMAX) of the central enlarged lower surface of the distribution plate 2 and the pitch circle diameter (SUP) of the distribution holes 13 on the upper surface of the porous plate 4 are made substantially the same. By doing so, the polymer that has passed through the path of the maximum residence time in the distribution plate 2 can be led to the distribution hole 13 in the shortest residence time on the downstream side of the distribution plate 2. In this case, it is preferable that the maximum diameter (DMAX) of the central enlarged lower surface and the pitch circle diameter (SUP) of the distribution hole 13 are the same, because the effect of shortening the residence time is most preferable, but the pitch circle diameter (SUP) is the largest. Similar effects can be obtained even when the diameter (DMAX) is in the range of + 5% to -15%.

  More preferably, the pitch circle diameter (SLP) of the distribution holes 13 on the lower surface of the perforated plate 4 and the pitch circle diameter (DUP) of the introduction holes 14 on the upper surface of the spinneret 5 are the same. By doing so, the polymer guided to the distribution hole 13 with the shortest residence time on the downstream side of the distribution plate 2 can be further guided to the introduction hole 14 with the shortest residence time and discharged from the discharge hole 15. . In this case, it is preferable that the pitch circle diameter (SLP) of the distribution hole 13 and the pitch circle diameter (DUP) of the introduction hole 14 are the same, because the effect of shortening the residence time is most preferable, but the pitch circle diameter (DUP) is The same effect can be obtained even when the pitch circle diameter (SLP) is in the range of + 5% to -15%. Here, as described above, if the introduction holes 14 are arranged in a single row, the pitch circle diameter may be a pitch circle diameter (DUP), and the introduction holes 14 may be arranged in a plurality of rows. For example, the pitch circle diameter (DUP) is the diameter of the imaginary circle that is the average value of the innermost pitch circle diameter and the outermost pitch circle diameter.

  Note that the residence time generated in the distribution plate 2 is not reduced in the downstream filtration unit 22, the perforated plate 4, and the spinneret 5, but rather is gradually increased. It is preferable to reduce the residence time at as much as possible. In particular, in the route (route MAX) having the longest residence time, the proportion of the residence time is large in the outer peripheral upper surface flow path 10, and reducing this gap is effective in reducing the residence time. Further, in order to reduce the channel volume and reduce the residence time in the central enlarged flow channel 9 and the outer peripheral lower surface flow channel 11, the flow channel height is lowered, that is, the central enlarged lower surface 27 and the outer peripheral lower surface 26. It is preferable to increase the widening angle of the taper.

  Further, the flow rate ratio of the polymer passing through the central flow path 8 of the distribution plate 2 and the outer peripheral upper surface flow path 10 is in the range of the central flow path 8: outer peripheral upper surface flow path 10 = 3: 7 to 7: 3. Is preferred. When the polymer flow rate ratio passing through the central flow path 8 is increased, the pressure loss in the central flow path 8 becomes too large, and when the polymer flow rate ratio passing through the outer peripheral upper surface flow path 10 is increased, the central flow rate 8 And the difference in the residence time of the polymer passing through the outer peripheral upper surface flow path 10 is enlarged, and the dispersion of the residence time is increased.

  Another embodiment having the same effect as that of the embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 3, at the boundary between the perforated plate 4 and the spinneret 5, the outer peripheral edge of the distribution hole 13 on the lower surface of the perforated plate 4 and the outer peripheral edge of the introduction hole 14 on the upper surface of the spinneret 5 are matched. Also good. Here, “the outer peripheral edge matches” means that the shape of the opening of the distribution hole 13 on the lower surface of the perforated plate 4 and the shape of the opening of the introduction hole 14 that faces the distribution hole 13 on the upper surface of the spinneret 5. Are the same, and the outer peripheries of the respective shapes coincide and overlap. When the outer peripheral edge of the distribution hole 13 and the outer peripheral edge of the introduction hole 14 are arranged to coincide with each other, an unnecessary flow path space is eliminated between the perforated plate 4 and the spinneret 5, and abnormal retention of the polymer can be suppressed. As a result, the residence time and the residence time variation can be suppressed.

  In addition, as shown in FIG. 4, a plurality of discharge holes 15 may be communicated with one introduction hole 14. In this case, in order to secure a space for disposing the discharge holes 15, it is necessary to increase the diameter of the introduction holes 14. However, if the diameter of the distribution holes 13 is increased in accordance with the diameter of the introduction holes 14, the flow path space is increased. There is concern that the residence time will increase and the residence time will increase. Therefore, the hole diameter of the distribution hole 13 is made smaller than the hole diameter of the introduction hole 14 from the upper surface to the vicinity of the lower surface of the porous plate 4, and the hole diameter is gradually widened near the lower surface of the porous plate 4. It is preferable that the outer peripheral edge of the distribution hole 13 on the lower surface of the perforated plate 4 and the outer peripheral edge of the introduction hole 14 on the upper surface of the spinneret 5 are made to coincide with each other by using a method such as making the same hole diameter as the introduction hole 14 on the lower surface. .

  Further, as shown in FIG. 5, the distribution holes 13 on the upper surface of the porous plate 4 have a plurality of circumferential arrangements, and the outermost periphery of these circumferential arrangements has a pitch circle diameter (SUP). The flow path may be configured such that the distribution holes 13 are arranged in a circumferential arrangement in one row. With this configuration, the polymer flowing into the distribution holes 13 arranged on the innermost periphery of the upper surface of the perforated plate 4 is guided to the introduction holes 14 of the spinneret 5 through the shortest path, so that the minimum polymer residence time is further increased. Can be small. However, since the residence time variation slightly increases accordingly, it is preferable to reduce the hole diameter of the distribution hole 13 or to appropriately adjust the pitch circle diameter of the distribution hole 13 arranged on the upper surface of the porous plate 4. When it is desired to reduce the minimum polymer residence time while maintaining the variation in the polymer residence time, the configuration shown in FIG. 5 may be adopted.

  Next, the members common to the embodiment of the present invention shown in FIG. 1 and the spin pack 7 of the other embodiments of the present invention shown in FIGS. 3, 4, and 5 and the shapes of the members are described in detail. explain.

  The hole diameter of the polymer inflow hole 17 in the spinneret 5 of the embodiment of the present invention is preferably the same as that of the polymer pipe located on the upstream side, and the hole diameter is from φ5 mm so that the flow path pressure loss does not become excessive. A range of φ10 mm is preferable.

The inclination angle θ of the distribution plate 2 in the spinneret 5 of the embodiment of the present invention is preferably in the range of 5 ° to 15 °. In that case, it is preferable that the inclination angle of the upper lid 1 is equal so that the flow path gap of the outer peripheral upper surface flow path 10 is constant. When the inclination angle θ is extremely smaller than 5 °, the flow direction of the polymer when flowing from the polymer inflow hole 17 to the outer peripheral upper surface flow path 10 changes abruptly, so that abnormal retention may easily occur. . When the inclination angle θ is extremely larger than 15 °, the flow path length of the outer peripheral upper surface flow path 10 becomes large, and a problem that the residence time increases may occur.
The arrangement of the discharge holes 15 in the spinneret 5 of the embodiment of the present invention may be appropriately determined according to the number of multifilament yarns, the number of yarns, and the cooling device 20. In that case, in the annular inward cooling device that blows cooling air from the outer periphery to the inner periphery, or the annular outward cooling device that blows cooling air from the inner periphery to the outer periphery as the cooling device 20, the discharge holes 15 are arranged in one or more rows. In order to suppress the yarn unevenness, it is preferable to arrange them in a crossover shape. Of course, even in a one-way cooling device that blows cooling air from one direction, the discharge holes 15 may be arranged in a row or a plurality of rows in a circumferential shape.

  In addition, the discharge hole 15 and the introduction hole 14 of the embodiment of the present invention are not limited to a round shape in a cross section perpendicular to the polymer flow path direction, and may have an irregular cross-sectional shape or a hollow cross-sectional shape. In addition, the distribution hole 13 of the embodiment of the present invention is not limited to a round cross section in a direction perpendicular to the polymer flow path direction, and may have an irregular cross sectional shape or a hollow cross sectional shape. By reducing the hole cross-sectional area to such an extent that it does not become extremely large and increasing the number of distribution holes 13 arranged circumferentially, it is possible to prevent the polymer flowing into the distribution holes 13 from flowing in the circumferential direction. As a result, the residence time and the residence time variation can be suppressed.

  The present invention is an extremely versatile invention and can be suitably applied to all multifilament yarns obtained by known spinneret and filament yarn production methods. Therefore, it is not particularly limited by the polymer constituting the multifilament yarn. For example, polyesters, polyamides, polyphenylene sulfides, polyolefins, polyethylenes, polypropylenes, etc. can be cited as examples of polymers constituting the multifilament yarn suitable for the present invention.

  Furthermore, in the above-mentioned polymers, matting agents such as titanium dioxide, silicon oxide, kaolin, anti-coloring agents, stabilizers, antioxidants, deodorizers, flame retardants, yarn friction, as long as yarn production stability is not impaired. Various functional particles such as a reducing agent, a color pigment, and a surface modifier, additives such as organic compounds may be contained, and copolymerization may be included.

  Moreover, the polymer used for this invention may be comprised by a single component, or may be comprised by multiple components, and in the case of a multiple component, structures, such as a core sheath and a side-by-side, are mentioned, for example. In addition, the cross-sectional shape of the multifilament yarn may be an irregular shape such as a circle, a triangle, a flat shape, or a hollow shape.

  Further, the single yarn fineness of the multifilament yarn is not particularly limited, but the smaller the single yarn fineness, the clearer the difference from the prior art.

  Further, the number of single yarns of the multifilament yarn is not particularly limited, but as the number of single yarns of the multifilament yarn is larger, the difference from the conventional technique becomes clearer. Furthermore, the number of yarns of the multifilament yarn is not particularly limited, and may be one yarn or may be two or more yarns, but the more yarns the more The difference from the conventional technology becomes clear.

  In the case of producing a multifilament yarn using the spinneret 1 of the present invention, the polymer is discharged from the spinneret 1, cooled by the cooling air blown from the cooling device 28, taken up, and then wound up. The film may be stretched or stretched, and may be wound without being stretched.

  Each characteristic value used in the examples was determined by the following measurement method.

(1) Fineness variation value CV (%), fineness unevenness The fineness of the yarn of the multifilament yarn was measured according to JIS L 1013-1999 8.3.1 Fineness Fineness Fineness A Method. The fineness fluctuation rate CV (%) was calculated from the following formula and used for evaluation of fineness spots. Fineness variation rate CV (%) is “less than 1.0%”, “1.0% or more and less than 1.5%” is ◯, “1.5% or more and less than 2.0%” is △, “2 .0% or more "was evaluated as x.
Fineness variation rate CV (%) = (standard deviation of yarn fineness) / (arithmetic average of yarn fineness) × 100.

(2) Thread breakage Two tons of yarn was spun and evaluated by the number of thread breaks during this period. “Less than 1.5 times” is marked with “◎”, “1.5 times or more but less than 3 times” is marked with “◯”, “3 times or more but less than 5 times” is marked with Δ, and “5 times or more” is marked with “X”.

(3) Intrinsic viscosity [η]
Measurement was performed at 25 ° C. using orthochlorophenol as a solvent.

(4) 98% sulfuric acid relative viscosity [ηr]
(A) A sample is weighed and dissolved in 98% by weight concentrated sulfuric acid so that the sample concentration (C) is 1 g / 100 ml.
(B) The drop rate (T1) at 25 ° C. of the solution of item (a) is measured with an Ostwald viscometer.
(C) Measure the drop rate (T2) at 25 ° C. of 98% by weight concentrated sulfuric acid not dissolving the sample.
(D) The 98% sulfuric acid relative viscosity (ηr) of the sample is calculated by the following formula. The measurement temperature is 25 ° C.
[Ηr] = (T1 / T2) + {1.891 × (1.000−C)}.

Example 1
A polymer of nylon 6 (chip with 98% sulfuric acid relative viscosity [ηr] 2.8, melting temperature 260 ° C.) is melted and discharged from the following spinning pack 7, and then steam is sprayed onto the die surface by the steam applicator 21 and cooled. Cooled by apparatus 20. Thereafter, refueling, entanglement treatment, and hot drawing were performed, and a multifilament yarn was manufactured by taking up with a winding roller at a speed of 4000 m / min.
As a result of producing 10 dtex, 18 filament yarns and 6 yarns of polyamide fiber, the fineness variation rate was 0.6%. As shown in Table 1, the yarn breakage during spinning was the best result, and the fineness unevenness of the obtained fiber was also the best result.

[Spinning pack]
As shown in FIG. 1, the upper lid 1, the distribution plate 2, the filter layer 3, the filter 16, the perforated plate 4, and the spinneret 5 were used.
The hole diameter of the central flow path 8 of the distribution plate 2 was φ2.5 mm, the gap between the outer peripheral upper surface flow paths 10 was 0.5 mm, and the maximum diameter (DMAX) of the central enlarged lower surface was φ70 mm.
The hole diameter of the distribution hole 13 of the perforated plate 4 was φ1.0 mm, and 144 pieces were provided in one circumferential row. The pitch circle diameter (SUP) on the upper surface and the pitch circle diameter (SLP) on the lower surface were the same, and were set to 70 mm.
The diameter of the introduction hole 14 of the spinneret 5 is φ1.5 mm, the diameter of the discharge hole 15 is φ0.17 mm, the pitch circle diameter (DUP) is two circumferential rows of φ68 mm and φ72 mm, and the virtual pitch circle diameter is φ70 mm. did.

(Example 2)
Spinning was performed with the same polymer, the same fineness and the same number of yarns as in Example 1 except that the following spinning pack was used.
As a result of producing the polyamide fiber, the fineness fluctuation rate was 0.8%. As shown in Table 1, the yarn breakage during spinning was the best result, and the fineness unevenness of the obtained fiber was also the best result.

[Spinning pack]
As shown in FIG. 5, the upper lid 1, the distribution plate 2, the filter layer 3, the filter 16, the perforated plate 4, and the spinneret 5 were used.
The flow path structure was such that the distribution holes 13 were arranged in two circumferential rows on the upper surface of the perforated plate 4 and the circumferential row was arranged in the lower surface. The hole diameter of the distribution hole 13 is φ2.5 mm, the pitch circle diameter on the inner peripheral side on the upper surface is φ50 mm, the pitch circle diameter on the outer peripheral side is φ70 mm (that is, the pitch circle diameter (SUP) on the upper surface is φ70 mm), and the pitch circle on the lower surface The diameter (SLP) was set to φ70 mm, and 36 pieces were provided circumferentially.
The other top lid 1, distribution plate 2, filter layer 3, filter 16, and spinneret 5 were the same as the spin pack used in Example 1.

(Example 3)
Spinning was performed with the same polymer, the same fineness and the same number of yarns as in Example 1 except that the following spinning pack was used.
As a result of producing the polyamide fiber, the fineness variation rate was 1.3%. As shown in Table 1, the yarn breakage during spinning was the best result, and the fineness unevenness of the obtained fiber was good.

[Spinning pack]
As shown in FIG. 4, the upper lid 1, the distribution plate 2, the filter layer 3, the filter 16, the perforated plate 4, and the spinneret 5 were used.
The distribution holes 13 of the perforated plate 4 have a hole diameter of φ1.5 mm, a pitch circle diameter (SUP) and a pitch circle diameter (SLP) of φ70 mm, and 36 are arranged in one circumferential row. The distribution hole 13 is a tapered flow path in which the hole diameter gradually increases near the lower surface of the porous plate 4 and the hole diameter becomes φ4.0 mm on the lower surface.
The diameter of the introduction hole 14 of the spinneret 5 is φ4.0 mm, the pitch circle diameter (DUP) is φ70 mm, and 36 pieces are provided in one circumferential line. The outer peripheral edge of the distribution hole 13 and the outer peripheral edge of the introduction hole 14 Is configured to match. The hole diameter φ of the discharge holes 15 is 0.17 mm, and three discharge holes 15 are formed for one introduction hole 14.
The other top lid 1, distribution plate 2, filter layer 3, and filter 16 were the same as the spin pack used in Example 1.

(Comparative Example 1)
In the spinning pack 7 used in Example 1, the maximum diameter (DMAX) of the central enlarged lower surface of the distribution hole 2 was changed to φ30 mm, and the other polymers were equivalent using the same spinning pack 7 as in Example 1. Spinning with fineness and number of yarns.
As a result of producing the polyamide fiber, the fineness variation rate was 2.1%. As shown in Table 1, the yarn breakage during spinning deteriorated, and the fineness unevenness of the obtained fiber also deteriorated.

(Comparative Example 2)
In the spinning pack 7 used in Example 2, the distribution plate 2 was removed, and the others were spun with the same polymer, fineness, and number of yarns using the same spinning pack 7 as in Example 2.
As a result of producing the polyamide fiber, the fineness variation rate was 2.4%. As shown in Table 1, yarn breakage during spinning was worse than that of Comparative Example 1, and fineness unevenness of the obtained fiber was worse.

(Comparative Example 3)
Spinning was carried out with the same polymer, the same fineness and the same number of yarns as in Example 1 except that the following spinning pack was used.
As a result of producing the polyamide fiber, the fineness variation rate was 2.2%. As shown in Table 1, the yarn breakage during spinning deteriorated, and the fineness unevenness of the obtained fiber also deteriorated.

[Spinning pack]
As shown in FIG. 8, the upper lid 1, the distribution plate 2, the filter layer 3, the filter 16, the perforated plate 4, and the spinneret 5 were used.
The hole diameter of the distribution hole 13 of the porous plate 4 was φ1.5 mm, and 160 distribution holes 13 were formed on the entire surface of the porous plate 4.
The other top lid 1, distribution plate 2, filter layer 3, filter 16, and spinneret 5 were the same as the spin pack used in Example 3.

[Summary]
In all of the spinning packs of Examples 1 to 3, the maximum diameter (DMAX) of the central enlarged lower surface of the distribution plate 2 and the pitch circle diameter (SUP) of the distribution holes on the upper surface of the porous plate 4 are the same. Both the yarn breakage and the fineness unevenness of the obtained fiber were good results.

  In the second embodiment, the distribution holes 13 on the upper surface of the perforated plate 4 are arranged in two rows, and the polymer can pass through the distribution holes 13 on the inner peripheral side. The shortest value of can be further shortened. However, since the dispersion of the residence time slightly increased, the fineness fluctuation rate was slightly deteriorated as compared with Example 1.

  In Example 3, the outer peripheral edge of the distribution hole 13 on the lower surface of the perforated plate 4 and the outer peripheral edge of the introduction hole 14 on the upper surface of the spinneret 5 coincide with each other, and it is unnecessary at the boundary between the perforated plate 4 and the spinneret 5. It was possible to reduce the number of polymer retention parts. However, since the flow passage cross-sectional area of the introduction hole 14 was increased, the residence time was increased, and the fineness variation rate was slightly deteriorated as compared with Example 1.

  By comparing Example 1 with Comparative Example 1, the maximum diameter (DMAX) of the central enlarged lower surface of the distribution plate 2 and the pitch circle diameter (SUP) of the distribution holes 13 on the upper surface of the porous plate 4 are made the same. The path of the maximum residence time generated in the distribution plate 2 can be led to the distribution hole 13 and the introduction hole 14 with the shortest residence time, and as a result, the residence time and residence time variation can be reduced, and the fineness can be reduced. It can be seen that spots can be suppressed.

  From comparison between Example 2 and Comparative Example 2, it can be seen that by installing the distribution plate 2, the residence time of the polymer on the upstream side of the filter layer 3 can be significantly reduced, and as a result, fineness spots can be suppressed.

  As a result of comparison between Example 3 and Comparative Example 3, only by forming the distribution holes 13 on the entire surface of the porous plate 4, the polymer passing through the path of the maximum residence time generated in the distribution plate 2 is Since it is distributed to the plurality of distribution holes 13 arranged in the same manner and cannot be guided by the shortest path, the residence time is further increased and the residence time variation is increased, so that it can be seen that fineness spots cannot be suppressed as a result. .

  The present invention is not limited to the production method of spinning packs and multifilament yarns used in the solution spinning method, but can also be applied to the production method of spinning packs and multifilament yarns used in wet spinning methods and dry and wet spinning methods. Yes, but the scope of application is not limited to these.

DESCRIPTION OF SYMBOLS 1 Upper cover 2 Distribution plate 3 Filtration layer 4 Porous plate 5 Spinneret 6 Spin pack body 7 Spin pack 8 Central flow channel 9 Central expansion flow channel 10 Outer peripheral upper surface flow channel 11 Outer peripheral lower surface flow channel 12 Outer peripheral flow channel 13 Distribution hole 14 Introduction hole DESCRIPTION OF SYMBOLS 15 Discharge hole 16 Filter 17 Polymer inflow hole 18 Mixing block 19 Spin block 20 Cooling device 21 Steam supply device 22 Filtration part 23 Lower surface of upper cover 24 Outer surface of distribution plate 25 Outer surface of distribution plate 26 Outer surface of distribution plate 27 Distribution plate The central enlarged bottom surface of the DMAX The maximum diameter of the central enlarged flow path of the distribution plate SUP The pitch circle diameter of the distribution hole on the upstream side in the flow path direction of the thermoplastic polymer PCD
SLP Pitch circle diameter PCD of distribution hole downstream of thermoplastic polymer in flow path direction
DUP Pitch circle diameter PCD of introduction hole upstream of thermoplastic polymer flow path direction
θ Inclination angle

Claims (6)

A spinning pack for spinning a thermoplastic polymer as a filament yarn,
An upper lid formed with a polymer inflow hole and a lower surface that extends from the downstream opening of the polymer inflow hole toward the outer peripheral side and the downstream side;
Arranged on the downstream side of the upper lid, a central flow path, an outer peripheral upper surface extending from the upstream opening of the central flow path toward the outer peripheral side and the downstream side, and an outer periphery narrowing from the outer peripheral edge toward the central side and the downstream side A distribution plate formed with a lower surface and a central enlarged surface that extends from the downstream side opening of the central channel toward the outer peripheral side and the downstream side and is connected to the lower peripheral surface;
A filtration unit disposed downstream of the distribution plate;
A perforated plate that is arranged on the downstream side of the filtration unit and has a plurality of distribution holes arranged in a circumferential shape from the upper surface to the lower surface, and
A spinneret formed on the downstream side of the perforated plate and formed with introduction holes arranged circumferentially from the upper surface to the downstream side, and discharge holes communicating with the introduction holes and discharging thermoplastic polymer from the lower surface When,
Is stored in a cylindrical spinning pack body,
The distribution plate is disposed at a distance from the lower surface of the upper lid and the inner wall surface of the spin pack body, and an outer peripheral upper surface flow path is formed between the outer peripheral upper surface of the distribution plate and the lower surface of the upper lid. An outer peripheral lower surface flow path is formed between the outer peripheral lower surface of the plate and the filtration part, and the outer peripheral upper surface flow path and the outer peripheral lower surface flow path are a gap between the distribution plate and the inner wall surface of the spinning pack body. A central enlarged flow path communicating with the central flow path is formed between the central enlarged lower surface of the distribution plate and the filtration portion;
The spinning pack, wherein a pitch circle diameter of the distribution holes on the upper surface of the perforated plate is 85 to 105% of a maximum diameter of a central enlarged lower surface of the distribution plate.   The spinning pack according to claim 1, wherein the pitch circle diameter of the introduction holes on the upper surface of the spinneret is 85 to 105% of the pitch circle diameter of the distribution holes on the lower surface of the perforated plate.   The spinning pack according to claim 1 or 2, wherein the pitch circle diameter of the distribution holes on the upper surface of the perforated plate is the same as the maximum diameter of the lower central enlarged surface of the distribution plate.   The spinning pack according to any one of claims 1 to 3, wherein a pitch circle diameter of the introduction holes on the upper surface of the spinneret is the same as a pitch circle diameter of the distribution holes on the lower surface of the perforated plate.   The spinning pack according to any one of claims 1 to 4, wherein an outer peripheral edge of the distribution hole of the porous plate and an outer peripheral edge of the introduction hole of the spinneret coincide with each other at a boundary between the perforated plate and the spinneret.   A method for producing a filament yarn, wherein the spinning pack according to any one of claims 1 to 5 is used to spin a thermoplastic polymer as a filament yarn.

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