Composite spinneret and method of manufacturing composite fiber
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- TORAY INDUSTRIES INC
- Filing Date
- 2024-01-05
- Publication Date
- 2026-05-27
Smart Images
Figure IMGAF001_ABST
Abstract
Description
Field
[0001] The present invention relates to a composite spinneret, and a method for manufacturing a composite fiber using the same.Background
[0002] As a method for manufacturing a composite fiber, there is a composite spinning method using a core-sheath, side-by-side, or islands-in-the-sea composite spinneret. In this method, composite polymer streams can be precisely controlled by a composite spinneret, and a highly accurate cross-sectional shape of a yarn can be formed particularly in a travelling direction of the yarn. Here, as a method for manufacturing a composite fiber by a composite spinning method, chips as raw materials are extruded by an extruder for each component to form a polymer, and the polymer is guided to a spin pack through a polymer pipe installed in a heating box. Thereafter, respective component polymers pass through a filter medium / filter disposed in the spin pack to remove foreign substances, and is distributed by a porous plate. Thereafter, a method is employed in which respective component polymers join with each other at a spinneret to form a composite polymer stream, and the composite polymer stream is discharged from a final discharge hole of the spinneret. This method for manufacturing a composite fiber using a spinneret is extremely important in determining the cross-sectional shape of the yarn.
[0003] Particularly in recent years, a spinneret called a distribution type spinneret has been used as a method of precisely controlling the cross-sectional shape of the yarn. In the distribution type spinneret, a polymer flow path is formed by stacking a plurality of distribution plates, and after respective component polymers are distributed in large numbers in advance by the distribution plates, they are simultaneously discharged from the lowermost layer distribution plate and composited, so that a complicated cross section can be formed.
[0004] For example, Patent Literature 1 discloses that, in order to form various cross-sectional shapes with high accuracy, as an arrangement of discharge holes of a twocomponent polymer (A / B-component polymer) in a lowermost layer distribution plate, second discharge holes for discharging a B-component polymer as a sea component are arranged in three directions, four directions, or six directions around first discharge holes for discharging an A-component polymer as an island component, whereby an islands-in-the-sea composite fiber in which the island components do not join with each other and the island component is polygonal can be manufactured. Further, it is disclosed that a core-sheath type composite fiber can also be manufactured by collecting first discharge holes in a middle layer of a fiber cross section and collecting second discharge holes in an outer layer, and a composite fiber in which a core component has a star shape or a trilobal cross section can be manufactured by collecting the first discharge holes in a star shape or a trilobal shape.
[0005] In addition, as an example of a hole arrangement similar to that in Patent Literature 1, Patent Literature 2 discloses that an islands-in-the-sea composite fiber can be manufactured by arranging holes in a hexagonal lattice pattern.
[0006] Further, Patent Literature 3 discloses that a split type composite fiber can be manufactured by arranging discharge holes of an A-component polymer or a B-component polymer at the center and alternately arranging first discharge holes and second discharge holes over the circumferential direction on the outer peripheral side thereof.
[0007] Furthermore, Patent Literature 4 discloses a method for manufacturing an islands-in-the-sea composite fiber using a distribution plate-type spinneret in a hole arrangement different from those in Patent Literatures 1 and 2. Patent Literature 4 discloses various hole arrangements (arrangements of first discharge holes for discharging island component polymer and second discharge holes for discharging sea component polymer) as embodiments, and discloses that a region containing only a sea component can be relatively freely formed in a large number of composite fiber islands. Moreover, it is disclosed that an islands-in-the-sea composite fiber in which a sea component region is formed can be manufactured by discharging a core-sheath composite polymer in which an A-component polymer is coated on a B-component polymer from the first discharge holes and discharging a B-component polymer from the second discharge holes.Citation ListPatent Literature
[0008] Patent Literature 1: JP 2011-174215 A Patent Literature 2: JP 07-3529 A Patent Literature 3: JP 2008-38275 A Patent Literature 4: WO 2014 / 077359 A SummaryTechnical Problem
[0009] However, the conventional method for manufacturing a composite fiber has technical problems described below. Patent Literature 1 and Patent Literature 2 do not describe the detailed arrangement of the discharge holes, and there is a case where the cross-sectional shape of the island component or the core component fluctuates depending on the combination of polymers and the discharge conditions, so that it may be improved from the viewpoint of precisely controlling the desired cross-sectional shape. That is, since the second discharge holes are arranged close to the periphery of the first discharge holes of the lowermost layer distribution plate, the A-component polymer and the B-component polymer discharged from each discharge hole collide and join in a state where the flow velocity is high, and the interface between the A-component polymer and the B-component polymer is disturbed, and the cross-sectional shape may not be stabilized. In particular, when the difference in discharge amount between the A-component polymer and the B-component polymer is large, or when the difference in polymer viscosity is large, the interface may be destabilized.
[0010] Further, in the spinneret disclosed in Patent Literature 3, the first discharge holes and the second discharge holes of the lowermost layer distribution plate are alternately arrayed in the circumferential direction, but since the discharge holes of the respective polymer components are formed of a single hole in order to form one interface, the cross-sectional shape of the divided fiber may not be precisely controlled. In addition, since the discharge holes of the respective components are arranged close to each other, the interface between the polymers is disturbed similarly to the above, and the cross-sectional shape may not be stabilized.
[0011] Furthermore, with the spinneret disclosed in Patent Literature 4, an islands-in-the-sea composite fiber in which sea regions are relatively freely formed can be manufactured, but on the other hand, according to findings by the present inventors, since the distances between the first discharge holes (discharge holes of island component polymer or core-sheath composite polymer) and the second discharge holes (discharge holes of sea component polymer) are close to each other, the interface shape between the sea component polymer and the island component polymer becomes wavy due to the influence of the arrangement of the discharge holes, and a desired fiber cross section may not be obtained. If the interface is wavy, when the sea component polymer is dissolved after the composite fiber is manufactured, the solution does not enter the center of the composite fiber, and poor dissolution may occur. In addition, since a wavy shape remains in the fiber of the island component after the sea component polymer is dissolved, operability in the subsequent step may be deteriorated.
[0012] Therefore, the present invention solves the problems of the prior art, and provides a composite spinneret capable of forming a cross section of a composite fiber with high accuracy and maintaining high stability of the cross-sectional shape, and a method for manufacturing a composite fiber using the composite spinneret.Solution to Problem
[0013] [1] The present invention to solve the problems the above is a composite spinneret for discharging a composite polymer stream composed of two or more-component polymers. The composite spinneret includes: at least one distribution plate in which distribution holes and / or distribution grooves for distributing respective polymer components are formed; a lowermost layer distribution plate that is arranged on a downstream side of the distribution plate in a polymer spinning path direction and in which a plurality of first discharge holes for discharging a first polymer component and a plurality of second discharge holes for discharging a second polymer component different from the first polymer component are formed; and a discharge plate arranged on a downstream side of the lowermost layer distribution plate in the polymer spinning path direction and having a spinneret discharge hole for forming a composite polymer stream in which the first polymer component and the second polymer component join with each other. In the first discharge holes and the second discharge holes, all of the first discharge holes which satisfy the following condition 1 and all of the second discharge holes which satisfy the following condition 1 are configured to satisfy the following condition 2.
[0014] Condition 1: the first discharge holes and the second discharge holes for respectively discharging the first polymer component and the second polymer component sandwich an interface in a range forming either a straight line or a smooth curve of an interface between the first polymer component and the second polymer component in a cross section of the composite polymer stream in a direction perpendicular to the polymer spinning path direction.
[0015] Condition 2: an arbitrary first discharge hole is defined as a discharge hole 1a, a first discharge hole adjacent to the first discharge hole 1a at a shortest center-to-center distance with respect to the first discharge hole 1a is defined as a discharge hole 1b, a second discharge hole adjacent to the discharge hole 1a at a shortest center-to-center distance with respect to the discharge hole 1a is defined as a discharge hole 4b, a second discharge hole adjacent to the discharge hole 4b at a shortest center-to-center distance with respect to the discharge hole 4b is defined as a discharge hole 4c, and a center-to-center distance L AB between the discharge hole 1a and the discharge hole 4b is twice or more a center-to-center distance L A between the discharge hole 1a and the discharge hole 1b and is twice or more a center-to-center distance L B between the discharge hole 4b and the discharge hole 4c.
[0016] Moreover, the composite spinneret of the present invention is preferably the following [2] or [3]. [2] The composite spinneret according to [1], wherein all of the first discharge holes which satisfy the condition 1 are arranged to be aligned on either a straight line or a smooth curve, and all of the second discharge holes which satisfy the condition 1 are arranged to be aligned on either a straight line or a smooth curve. [3] The composite spinneret according to [2], wherein the first discharge holes which satisfy the condition 1 and the second discharge holes which satisfy the condition 1 are arranged at line-symmetric positions with respect to a center line between a row of the first discharge holes which satisfy the condition 1 and a row of the second discharge holes which satisfy the condition 1. [4] A method for manufacturing a composite fiber, of the present invention, includes manufacturing a composite fiber by a composite spinning machine using the composite spinneret according to any one of [1] to [3]. [5] The method for manufacturing a composite fiber according to [4], wherein a ratio of a discharge amount of the second polymer component discharged from one of the second discharge holes to a discharge amount of the first polymer component discharged from one of the first discharge holes is 0.3 or more and 3.3 or less. [6] The method for manufacturing a composite fiber according to [4] or [5], wherein a ratio of a melt viscosity of the first polymer component to a melt viscosity of the second polymer component is 0.2 or more and 5.0 or less.
[0017] In the present invention, the "distribution hole" refers to a hole which is formed by combining a plurality of distribution plates into one and plays a role of distributing a polymer in a polymer spinning path direction.
[0018] In the present invention, the "distribution groove" refers to a groove which is formed by combining a plurality of distribution plates into one and plays a role of distributing a polymer in a direction perpendicular to the polymer spinning path direction. Here, the distribution groove may be a long and thin hole (slit), or a long and thin groove may be cut.
[0019] In the present invention, the "polymer spinning path direction" refers to a main direction in which the respective polymer components flow from a distribution plate to a spinneret discharge hole of a discharge plate.
[0020] In the present invention, the "direction perpendicular to the polymer spinning path direction" refers a direction perpendicular to the main direction in which the respective polymer components flow from a distribution plate to a spinneret discharge hole of a discharge plate. Advantageous Effects of Invention
[0021] In accordance with the composite spinneret of the present invention, it is possible to smoothly form a polymer interface between heterogeneous polymers and maintain high dimensional stability of the interface form. Also, it is possible to form various fiber cross-sectional shapes with high accuracy.Brief Description of Drawings
[0022] FIG. 1 is a partially enlarged plan view of a lowermost layer distribution plate used in a composite spinneret of an embodiment of the present invention. FIG. 2 is a schematic sectional view of a composite spinneret according to an embodiment of the present invention. FIG. 3 is a schematic partial sectional view of a distribution plate and a lowermost layer distribution plate used in a composite spinneret of an embodiment of the present invention. FIG. 4 is a view taken in the direction of arrows X-X in FIG. 2. FIG. 5 is a schematic sectional view of a spin block using a composite spinneret according to an embodiment of the present invention. FIG. 6 is a partially enlarged plan view of a lowermost layer distribution plate according to another embodiment of the present invention. FIG. 7 is a partially enlarged plan view of a lowermost layer distribution plate according to another embodiment of the present invention. FIG. 8 is a sectional view showing a cross-sectional shape of a typical composite fiber manufactured with a composite spinneret according to an embodiment of the present invention. FIG. 9 is a partially enlarged plan view of a lowermost layer distribution plate used in a conventional example. FIG. 10 is an enlarged view of an interface of a composite polymer obtained when the lowermost layer distribution plate of FIG. 1 is used. FIG. 11 is an enlarged view of an interface of a composite polymer obtained when the lowermost layer distribution plate of FIG. 9 is used. FIG. 12 is a view for explaining the presence or absence of a cross section defect at a polymer interface of a composite fiber. FIG. 13 is a partially enlarged plan view of a lowermost layer distribution plate according to another embodiment of the present invention. Description of Embodiments
[0023] Hereinafter, while referring to drawings, an embodiment of a composite spinneret of the present invention will be described in detail. FIG. 2 is a schematic sectional view of a composite spinneret according to an embodiment of the present invention, and FIG. 4 is a view taken in the direction of arrows X-X in FIG. 2. FIG. 1 is a partially enlarged plan view of a lowermost layer distribution plate used in a composite spinneret of an embodiment of the present invention, and FIGS. 6 and 7 are partially enlarged plan views of a lowermost layer distribution plate according to another embodiment of the present invention. FIG. 5 is a schematic sectional view of a spin block using the composite spinneret according to the embodiment of the present invention. In addition, these are conceptual drawings for correctly expressing the essential points of the present invention and are simplified, and the composite spinneret of the present invention is not limited to these, and the numbers of holes and grooves, and a dimensional ratio of holes and grooves may be changed according to the embodiment.
[0024] As shown in FIG. 5, a composite spinneret 18 according to an embodiment of the present invention is fitted in a spin pack 15 and fixed in a spin block 16, and a cooling apparatus 17 is configured immediately below the composite spinneret 18. Therefore, a first polymer component guided to the composite spinneret 18 and at least one type of second polymer component different from the first polymer component respectively pass through a distribution plate 6 and a lowermost layer distribution plate 5, and are discharged from a spinneret discharge hole 21 of a discharge plate 10 and then cooled by an air stream blown out from the cooling apparatus 17 and provided with a spinning oil, and then the polymers are taken up as composite fibers. In addition, in FIG. 5, the annular cooling apparatus 17 which blows an air stream annuallyinwardly is employed; however, a cooling apparatus 17 which blows an air stream from one direction may be used. Also, as a member disposed to the upstream side of the distribution plate 6, a flow path or the like used in the existing spin pack 15 may be used, and the member does not need to be exclusive.
[0025] As shown in FIG. 2, the composite spinneret 18 used in an embodiment of the present invention is configured by laminating at least one distribution plate 6, the lowermost layer distribution plate 5 and the discharge plate 10 in turn, and particularly the distribution plate 6 and the lowermost layer distribution plate 5 are preferably composed of a thin plate. In this case, the distribution plate 6 and the lowermost layer distribution plate 5, and the discharge plate 10 are positioned so as to be aligned with a center position (core) of the spin pack 15 by a locating pin, laminated, and then may be fixed by a screw, bolt or the like, or may be metal-joined by thermocompression bonding.
[0026] Therefore, as shown in FIG. 3, a first polymer component 13 supplied to the distribution plate 6 passes through distribution grooves 8 and distribution holes 7 of the distribution plate 6 formed by laminating at least one distribution plate 6, and then is discharged from first discharge holes 1 for discharging the first polymer component of the lowermost layer distribution plate 5. Also, although not illustrated, the second polymer component similarly passes through the distribution grooves 8 and the distribution holes 7 of the distribution plate 6 and is discharged from second discharge holes 4 of the lowermost layer distribution plate 5. In the distribution plate 6 and the lowermost layer distribution plate 5, the first polymer component and the second polymer component do not join with each other and are distributed in the respective flow paths.
[0027] Moreover, as shown in FIG. 2, in a discharge introduction hole 11, the first polymer component discharged from the first discharge holes 1 and the second polymer component discharged from the second discharge holes 4 join with each other to form a composite polymer. Thereafter, the flow of composite polymer is contracted by a flow contracting hole 12 and discharged from the spinneret discharge hole 21. As shown in FIG. 4, the polymer components are discharged from discharge holes of the respective components of the lowermost layer distribution plate 5, and a joined composite polymer is discharged from the spinneret discharge hole 21, thereby one composite fiber is formed. The lowermost layer distribution plate 5 in FIG. 4 shows a schematic view in which four composite fibers can be formed.
[0028] Here, a principle of the most important point of the present invention will be described, by which an interface i between the first polymer component 13 and the second polymer component 14 can be formed in a straight line or a smooth curve in a cross section of the composite polymer stream in the direction perpendicular to the polymer spinning path direction. Here, the "smooth curve" refers to an interface in which an average deviation rate X calculated by the method described in "(1) Presence or absence of cross section defect of composite fiber" in Examples is less than 30%. When the polymer interface of the composite polymer stream is formed using the composite spinneret of the distribution type spinneret of the conventional example, as shown in FIG. 11, the interface i between the first polymer component 13 and the second polymer component 14 becomes wavy, and the composite polymer is discharged as it is from the spinneret discharge hole 21, so that a composite fiber having a distorted cross-sectional shape is obtained. The reason for this will be described with reference to FIG. 9.
[0029] FIG. 9 shows a lowermost layer distribution plate 5' of the conventional example, and at the boundary between the first polymer 13 and the second polymer 14, the first discharge holes 1 and the second discharge holes 4 are respectively arranged in rows. It will be described such that, in the discharge holes, an arbitrary first discharge hole 1 is defined as a discharge hole 1 (1a), a first discharge hole 1 adjacent to the discharge hole 1 (1a) at the shortest center-to-center distance with respect to the discharge hole 1 (1a) is defined as a discharge hole 1 (1b), a second discharge hole 4 adjacent to the discharge hole 1 (1a) at the shortest center-to-center distance with respect to the discharge hole 1 (1a) is defined as a discharge hole 4 (4b), and a second discharge hole 4 adjacent to the discharge hole 4 (4b) at the shortest center-to-center distance with respect to the discharge hole 4 (4b) is defined as a discharge hole 4 (4c). In the conventional example, since the discharge hole 1 (1a) and the discharge hole 4 (4b) are arranged very close to each other, before the first polymer components 13 discharged from the discharge hole 1 (1a) and the discharge hole 1 (1b) join with each other, and before the second polymer components 14 discharged from the discharge hole 4 (4b) and the discharge hole 4 (4c) join with each other, the first polymer component 13 discharged from the discharge hole 1 (1a) joins with the second polymer component 14 discharged from the discharge hole 4 (4b) closest to the discharge hole 1 (1a). Therefore, a polymer interface is determined at a position where the polymer components initially join with each other. On the other hand, since the adjacent discharge holes of the same polymer component (the discharge hole 1 (1a) and the discharge hole 1 (1b), the discharge hole 4 (4b) and the discharge hole 4 (4c)) join each other thereafter, a time difference occurs in determination of the interface position. As a result, the interface i of the polymer fluctuates, and it becomes difficult to form a smooth shape.
[0030] Accordingly, in the distribution type spinneret, it is an extremely important technology to properly arrange the discharge holes of the respective components of the lowermost layer distribution plate 5 and to supply an appropriate amount of polymer to form a composite polymer stream, for manufacturing composite fibers in various forms. Thus, the present inventors have made earnest investigations concerning the above-mentioned problems, and consequently they have found a new technology of the present invention.
[0031] In the lowermost layer distribution plate 5 of the embodiment of the present invention, as shown in FIG. 1, a plurality of first discharge holes 1 for discharging one type of polymer component (first polymer component 13) and a plurality of second discharge holes 4 for discharging a polymer component different from the first polymer component (second polymer component 14) are respectively linearly arranged in rows. Here, as in the description of the conventional example, an arbitrary first discharge hole 1 is defined as a discharge hole 1 (1a), a first discharge hole 1 adjacent to the discharge hole 1 (1a) at the shortest center-to-center distance with respect to the discharge hole 1 (1a) is defined as a discharge hole 1 (1b), a second discharge hole 4 adjacent to the discharge hole 1 (1a) at the shortest center-to-center distance with respect to the discharge hole 1 (1a) is defined as a discharge hole 4 (4b), and a second discharge hole 4 adjacent to the discharge hole 4 (4b) at the shortest center-to-center distance with respect to the discharge hole 4 (4b) is defined as a discharge hole 4 (4c).
[0032] In the lowermost layer distribution plate 5 of the embodiment of the present invention, the first discharge holes 1 and the second discharge holes 4 for respectively discharging the first polymer component 13 and the second polymer component 14, which sandwich an interface in a range forming either a straight line or a smooth curve of the interface i between the first polymer component 13 and the second polymer component 14 in the cross section of the composite polymer stream in the direction perpendicular to the polymer spinning path direction, are arranged such that a center-to-center distance L AB between the discharge hole 1 (1a) and the discharge hole 4 (4b) is twice or more a center-to-center distance L A between the discharge hole 1 (1a) and the discharge hole 1 (1b) and is twice or more a center-to-center distance L B between the discharge hole 4 (4b) and the discharge hole 4 (4c).
[0033] As described above, in the lowermost layer distribution plate 5 of the embodiment of the present invention, the discharge holes are arranged such that the distance between the discharge hole 1 (1a) and the adjacent discharge hole 4 (4b) is farther than that in the conventional lowermost layer plate 5'. Therefore, after the first polymer components 13 discharged from each of the discharge hole 1 (1a) and the adjacent discharge hole 1 (1b) join with each other and the second polymer components 14 discharged from each of the discharge hole 4 (4b) and the adjacent discharge hole 4 (4c) join with each other, the first polymer component 13 and the second polymer component 14 can join with each other to form a composite polymer stream. As a result, it is possible to reduce the difference in joining time due to the difference in the interface position, to reduce the fluctuation of the interface i of the polymer, and to form the interface having a smooth shape as shown in FIG. 10.
[0034] Here, when the distance L AB is less than twice the distance L A , before the first polymer components 13 discharged from each of the discharge hole 1 (1a) and the adjacent discharge hole 1 (1b) join with each other, the first polymer component 13 discharged from the discharge hole 1 (1a) and the second polymer component discharged from the adjacent discharge hole 4 (4b) join with each other. Therefore, as described above, fluctuation may occur in the polymer interface, and it is difficult to form a smooth interface shape. Similarly, even when the distance L AB is less than twice the distance L B , before the second polymer components 14 discharged from each of the discharge hole 4 (4b) and the adjacent discharge hole 4 (4c) join with each other, the second polymer component discharged from the discharge hole 4 (4b) and the first polymer component 13 discharged from the adjacent discharge hole 1 (1a) join with each other. Therefore, fluctuation may occur in the polymer interface, and it is difficult to form a smooth interface shape.
[0035] In order to simplify the description, the position of the discharge hole 1 (1a) as a reference is determined and described in FIG. 1, but in the lowermost layer distribution plate 5 of the embodiment of the present invention, an arbitrary first discharge hole 1 arranged in a region where the interface between the first polymer component 13 and the second polymer component 14 is desired to be a straight line or a smooth curve can be set as the discharge hole 1 (1a) as a reference.
[0036] Also, in the lowermost layer distribution plate 5 of the embodiment of the present invention, the first discharge holes 1 and the second discharge holes 4 are arranged in rows at the interface i between the first polymer 13 and the second polymer 14. The numbers of the first discharge holes 1 and the second discharge holes 4 arranged may be different from each other, and the array pitch of the first discharge holes 1 and the array pitch of the second discharge holes 4 may be different from each other. Preferably, the discharge holes are arranged at line-symmetric positions on a one-to-one basis with respect to a center line between a row of the first discharge holes 1 and a row of the second discharge holes 4, so that the distance L AB can be kept constant, and the difference in joining time in the rows can be reduced.
[0037] Further, as in a lowermost layer distribution plate 5A according to another embodiment of the present invention shown in FIG. 6, each of first discharge holes 1 and second discharge holes 4 may form a row along a gentle curve. Thereby, the polymer interface of different components can form a gentle curve.
[0038] Furthermore, as in a lowermost layer distribution plate 5B according to another embodiment of the present invention shown in FIG. 7, first discharge holes 1 and second discharge holes 4 may form aggregates of a plurality of holes (hole group), and the discharge holes of either one component may form aggregates of a plurality of holes (hole group). In this case, the center of gravity of the hole group of the discharge holes is defined as a virtual group center P, and a distance L A , a distance L AB , and a distance L B are calculated from a center-to-center distance between the virtual group centers P.
[0039] Next, a method for manufacturing a composite fiber using the composite spinneret of the present invention will be described. In the method for manufacturing a composite fiber of the present invention, the composite spinneret 18 of the present invention may be used in a publicly known composite spinning machine. For example, in the case of melt spinning, as a spinning temperature, a temperature at which principally a polymer with a high melting point or high viscosity of two or more types of polymers exhibits flowability is selected. As the temperature exhibiting flowability, although depending on a molecular weight, a melting point of the polymer is a standard, and the spinning temperature may be set to melting point + 60°C or lower. When the spinning temperature is melting point + 60°C or lower, a reduction in molecular weight is suppressed without any thermal decomposition or the like of the polymer in the spin pack 15, and therefore, it is preferred. A spinning speed varies depending on the properties of the polymer and an object of the composite fiber, and is about 1 to 6000 m / min.
[0040] Further, the ratio of the discharge amount of the second polymer component 14 discharged from one second discharge hole 4 to the discharge amount of the first polymer component 13 discharged from one first discharge hole 1 of the lowermost layer distribution plate 5, 5A, or 5B is preferably 0.3 or more and 3.3 or less. Within this range, the interface between the first polymer component 13 and the second polymer component 14 is stabilized, and the form can be accurately maintained. When the ratio of the discharge amount from each discharge hole is less than 0.3 or more than 3.3, the polymer component with the larger discharge amount moves the polymer component with the smaller discharge amount away from the position of the discharge hole, so that the shape of the polymer interface is less likely to be smoothly formed.
[0041] Furthermore, the ratio of melt viscosity η1 of the first polymer component to melt viscosity η2 of the second polymer component used (= η1 / η2) is preferably 0.2 or more and 5.0 or less. Within this range, the interface between the first polymer component and the second polymer component is stabilized, and temporal fluctuation is reduced. When the ratio is less than 0.2 or more than 5.0, the polymer component on the low viscosity side easily surrounds the polymer component on the high viscosity side, and the shape of the polymer interface is less likely to be smoothly formed.
[0042] Next, a composite fiber obtained by the composite spinneret 18 of the present invention will be described. The composite fiber obtained by the composite spinneret 18 of the present invention means a fiber formed by combining two or more types of polymers, and refers to a fiber in which two or more types of polymers exist in various island forms in the fiber cross section. Here, needless to say, the two or more types of polymers includes that two or more types of polymers having different molecular structures such as polyester, polyamide, polyphenylene sulfide, polyolefin, polyethylene, and polypropylene are used; however, this also includes that within a range not impairing the stability of yarn-making and the like, addition amounts of delustering agents such as titanium dioxide; various functional particles such as silicon oxide, kaolin, anti-coloring agent, stabilizer, antioxidant agent, deodorant, flame retarder, anti-yarn friction agent, color pigment and surface modifier; and additives or particles of organic compounds are different, and that molecular weights thereof are different, and that copolymerization thereof is performed, and the like.
[0043] Also, a cross section of a single yarn of the composite fiber obtained by the method for manufacturing a composite fiber of the present invention may have a shape such as a triangle shape or a flat shape other than a circular shape in addition to a circular shape, or may be hollow. Further, the present invention is an extremely versatile invention, and it is not particularly limited by a single yarn fineness of the composite fiber, nor particularly limited by the number of single yarns of the composite fiber, nor particularly limited by the number of lines of yarns of the composite fiber, and may be one line of yarn or multi lines of two or more lines of yarns.
[0044] As described above, the composite fiber obtained by the method for manufacturing a composite fiber of the present invention refers to a fiber in which two or more types of different polymers form various island forms in a cross section perpendicular to the fiber axis direction. In that case, the island form is not limited, and as in the composite fiber 20 shown in FIG. 8(a), the interface between the second polymer component 14 which is one flat island component and the first polymer component 13 surrounding the second polymer component 14 may be configured linearly. Also, as the composite fiber 20A shown in FIG. 8(b), the interface of the second polymer component 14 which is an island component may be configured in a gentle curved shape. Further, as the composite fiber 20B shown in FIG. 8(c), the interface of the second polymer component 14 which is a large number of flat island components may be configured linearly. Furthermore, as the composite fiber 20C shown in FIG. 8(d), the second polymer component 14 which is a large number of island components may have a complicated shape, and a part of the interface may be configured linearly. The number of the island forms can be theoretically infinitely prepared as long as the space of the discharge surface of the lowermost layer distribution plate 5 allows, but the number of the island forms is preferably in a range of 2 to 10,000 as a practically feasible range.
[0045] Next, respective members and shapes of the respective members common to the composite spinneret 18 of an embodiment of the present invention shown in FIGS. 1, 2, 3, 4, 5, 6, 7, and 13 will be described in detail. A shape of the composite spinneret 18 in the present invention is not limited to a circular shape, and may be a tetragonal shape or a polygonal shape. Further, an array of the spinneret discharge holes 21 in the composite spinneret 18 may be appropriately determined according to the number of the composite fibers, the number of lines of yarns, and the cooling apparatus 17. With respect to the cooling apparatus 17, for an annular cooling apparatus, the spinneret discharge holes 21 may be arrayed in an annular form over one column or plural columns, and for a cooling apparatus of one way, the spinneret discharge holes 21 may be arrayed in a grid or staggered arrangement.
[0046] A cross section of the spinneret discharge hole 21 in the direction perpendicular to the polymer spinning path direction is not limited to a circular shape, and may be a cross section other than the circular shape or a hollow cross section. However, a cross section other than the circular shape is employed, a length of the spinneret discharge hole 21 is preferably lengthened in order to ensure the polymer metering capability.
[0047] Also, in the first discharge holes 1 and the second discharge holes 4 in the present invention, a cross section in the direction perpendicular to the polymer spinning path direction is not limited to a circular shape, and may be an ellipse or a rectangle. In this case, the center of gravity of the discharge holes is defined as the virtual group center P, and a distance L A , a distance L AB , and a distance L B are calculated from a center-to-center distance between the virtual group centers P.
[0048] Further, in the flow contracting hole 12 in the present invention, it is possible to inhibit unstable phenomena such as draw resonance of the composite polymer stream and supply the composite polymer stream stably by setting a taper angle θ of a flow path from the discharge surface of the lowermost layer distribution plate 5 to the spinneret discharge hole 21 to a range of 50 to 120°. Here, when the taper angle θ is less than 50°, the unstable phenomena of the composite polymer stream can be inhibited; however, the composite spinneret 18 itself grows in size, and when the taper angle θ is more than 120°, the unstable phenomena of the composite polymer stream may become more remarkable.
[0049] In addition, it is preferable that the hole diameter of the opening above the flow contracting hole 12 is configured to be larger than the outer diameter of a virtual circle 19 of the discharge hole group of the first discharge holes 1 and the second discharge holes 4 arranged on the discharge surface of the lowermost layer distribution plate 5, and the ratio of the cross-sectional area of the virtual circle 19 to the cross-sectional area of the discharge hole group is configured to be as small as possible. Thereby, widening of each polymer discharged from the discharge surface is suppressed, and the composite polymer stream can be stabilized.
[0050] Further, in one distribution plate 6 of the present invention, only the distribution hole 7 may be arranged, only the distribution groove 8 may be arranged, or the distribution hole 7 may be arranged on the upstream side of the distribution plate 6, and the distribution groove 8 (downstream side) may be arranged in communication therewith, or the distribution groove 8 may be arranged on the upstream side of the distribution plate 6, and the distribution hole 7 (downstream side) may be arranged in communication therewith.
[0051] Also, the method for manufacturing a composite fiber of the present invention is not limited to the application of the melt spinning method, and can also be applied to a wet spinning method, a dry-wet spinning method, and a dry spinning method. In the case of applying the wet spinning method, the composite spinneret 18 is immersed in a coagulation bath, and in the case of applying the dry spinning method, the composite spinneret 18 is installed above the liquid surface of a coagulation bath.
[0052] As described above, in the method for manufacturing a composite fiber of the present invention, since the cross-sectional shape can be arbitrarily controlled, a free form can be manufactured without being limited to the above form, and the composite fiber manufactured by the manufacturing method of the present invention can be formed into multipurpose fiber products such as fiber take-up package, tow, cut fiber, cotton, fiber ball, cord, pile, textile, nonwoven fabric, paper and liquid dispersion.Examples
[0053] Hereinafter, the effects of the composite spinneret of the present invention and the method for manufacturing a composite fiber will be specifically described with reference to Examples. In Examples and Comparative Examples, the composite fiber was spun using the composite spinneret of the present invention, and the presence or absence of a cross section defect of the composite fiber was determined.(1) Presence or absence of cross section defect of composite fiber
[0054] The fiber was continuously spun for 24 hours from the start of spinning, and then the obtained composite fiber was cut at an arbitrary position in the fiber axis direction, and the fiber cross section was photographed at a magnification of 1000 times with a VE-7800 scanning electron microscope (SEM) manufactured by KEYENCE CORPORATION. As shown in FIG. 12, an average value line g in a linear or curved range of the interface between a first polymer component and a second polymer component is derived, the average value line thereof is divided into N = 49 equal parts (i = N+1, i = 1, 2, 3... N+1), and the distance from the average value line at each equally divided position is defined as Li (i = 1, 2, 3... N+1). Then, average deviation η and average deviation rate X were calculated by the following equation, and when the average deviation rate X was 30% or more, the cross-sectional shape was determined to be defective, and when the average deviation rate X was less than 10%, the interface shape was determined to be good. Average deviation η = L 1 + L 2 + L 3 + … + L N + 1 / N + 1 (2) Melt viscosity of polymer
[0055] A polymer in a chip shape was dried to a water content of 200 ppm or less by a vacuum drying machine, and the melt viscosity was measured using "Capillograph 1B" manufactured by Toyo Seiki Seisaku-sho, Ltd., while stepwisely changing the strain rate. The measuring temperature was the same as the spinning temperature, and a melt viscosity at 1216 s -1< is described in Examples or Comparative Examples. Incidentally, the measurement was started at 5 minutes after charging a sample into a heating furnace, and it was performed in a nitrogen atmosphere.(3) Limiting viscosity [η]
[0056] The measurements were made at 25°C using orthochlorophenol as a solvent.(4) 98% Sulfuric acid relative viscosity [ηr]
[0057] (a) A sample is weighed and dissolved in 98% by mass concentrated sulfuric acid so that the sample has a viscosity C of 1 g / 100 ml. (b) The solution of item (a) is measured for the number of seconds of fall T1 using an Ostwald viscometer at 25°C. (c) The number of seconds of fall T2 of 98% by mass concentrated sulfuric acid in which the sample is not dissolved at 25°C is measured. (d) 98 mass% Sulfuric acid relative viscosity ηr of the sample is calculated by the following formula. The measuring temperature is 25°C. ηr = T 1 / T 2 + 1.891 × 1.000 − C [Example 1]
[0058] Polyethylene terephthalate (PET) having a limiting viscosity [η] of 0.65 and a melt viscosity of 210 Pa·s as a first polymer component, and polyethylene terephthalate (PET) having a limiting viscosity [η] of 0.59 and a melt viscosity of 130 Pa·s as a second polymer component were separately melted at 285°C. Using the following composite spinneret 18, these melted polymers were discharged at a ratio of the total discharge amount of the first polymer component / the total discharge amount of the second polymer component discharged from one spinneret discharge hole 21 of 15 / 85 (≈ 0.18). The discharged polymer was cooled by a cooling apparatus 17, and then subjected to oil feeding, entangling treatment, and thermal stretching, and wound at a speed of 1500 m / min by a winding roller to obtain non-stretched fibers of 168 dtex-18 filaments (single hole discharge amount: 4 g / min). The wound non-stretched fibers were stretched between rollers heated to 90°C and 130°C by 3.0 times to obtain composite fibers of 56 dtex / -18 filaments. As shown in FIG. 8(a), a cross section of the composite fiber had a straight line shape.
[0059] Here, in the lowermost layer distribution plate 5 of the composite spinneret 18 used in Example 1, as shown in FIG. 1, first discharge holes 1 and second discharge holes 4 for respectively discharging the first polymer component and the second polymer component are arranged in a linear range (range forming a straight long side) of an interface between the first polymer component and the second polymer component of the composite polymer stream. The number of the first discharge holes 1 per composite fiber is 40, and the number of the second discharge holes 4 per composite fiber is 30. These discharge holes linearly formed rows, and the first discharge holes 1 and the second discharge holes 4 were arranged line-symmetrically with respect to a center line between a row of the first discharge holes 1 and a row of the second discharge holes 4. Moreover, the center-to-center distance L A is set to 1 mm, the center-to-center distance L B is set to 1 mm, and the center-to-center distance L AB is set to 2.5 mm. The discharge holes are arranged such that the center-to-center distance L AB is 2.5 times the center-to-center distance L A , and the center-to-center distance L AB is 2.5 times the center-to-center distance L B . As described in Table 1, the average deviation rate of the interface shape of the fiber cross section was 1.3%, and there was no cross section defect, resulting in a good result. The ratio of the discharge amount of the second polymer component discharged from one second discharge hole 4 to the discharge amount of the first polymer component discharged from one first discharge hole 1 was about 0.13.[Example 2]
[0060] Using the same composite spinneret 18, polymer, and spinning conditions as in Example 1 except for changing the ratio of the total discharge amount of the first polymer component / the total discharge amount of the second polymer component discharged from one spinneret discharge hole 21 to 35 / 65 (≈ 0.54) to obtain composite fibers. As described in Table 1, the average deviation rate of the interface shape of the fiber cross section was 1.0%, and there was no cross section defect, resulting in a good result. The ratio of the discharge amount of the second polymer component discharged from one second discharge hole 4 to the discharge amount of the first polymer component discharged from one first discharge hole 1 was about 0.40.[Example 3]
[0061] Using the same polymer and spinning conditions as in Example 1 except for changing the lowermost layer distribution plate 5 and changing the ratio of the total discharge amount of the first polymer component / the total discharge amount of the second polymer component discharged from one spinneret discharge hole 21 to 25 / 75 (≈ 0.33) to obtain elliptical composite fibers as shown in FIG. 8(b). As shown in FIG. 6, in the lowermost layer distribution plate 5 of the composite spinneret 18, the first discharge holes 1 and the second discharge holes 4 are arranged in rows so as to form a smooth curve in a range where an elliptical long side is formed. The number of the first discharge holes 1 per composite fiber is 40, and the number of the second discharge holes 4 per composite fiber is 30. Moreover, the center-to-center distance L A is set to 1 mm, the center-to-center distance L B is set to 1 mm, and the center-to-center distance L AB is set to 2.3 mm. The discharge holes are arranged such that the center-to-center distance L AB is 2.3 times the center-to-center distance L A , and the center-to-center distance LAB is 2.3 times the center-to-center distance L B . As described in Table 1, the average deviation rate of the interface shape of the fiber cross section was 1.8%, and there was no cross section defect, resulting in a good result. The ratio of the discharge amount of the second polymer component discharged from one second discharge hole 4 to the discharge amount of the first polymer component discharged from one first discharge hole 1 was about 0.25.[Example 4]
[0062] Using the same polymer and spinning conditions as in Example 1 except for changing the lowermost layer distribution plate 5 to obtain composite fibers having a straight line cross-sectional shape as shown in FIG. 8(a). In a lowermost layer distribution plate 5C of the composite spinneret 18, as shown in FIG. 13, in a range where a straight long side is formed, all discharge holes of either one of the first discharge holes 1 and the second discharge holes 4 are moved by a half distance of the center-to-center distance L A in the straight longitudinal direction, and arranged in a staggered arrangement. The number of the first discharge holes 1 per composite fiber is 40, and the number of the second discharge holes 4 per composite fiber is 30. Moreover, the center-to-center distance L A is set to 1 mm, the center-to-center distance L B is set to 1 mm, and the center-to-center distance L AB is set to 2.6 mm. The discharge holes are arranged such that the center-to-center distance L AB is 2.6 times the center-to-center distance L A , and the center-to-center distance L AB is 2.6 times the center-to-center distance L B . As described in Table 1, the average deviation rate of the interface shape of the fiber cross section was 2.9%, and there was no cross section defect, resulting in a good result. The ratio of the discharge amount of the second polymer component discharged from one second discharge hole 4 to the discharge amount of the first polymer component discharged from one first discharge hole 1 was about 0.13.[Comparative Example 1]
[0063] Using the same composite spinneret 18 as in Example 1 except that the arrangement of the discharge holes of the lowermost layer distribution plate 5 is different, spinning was carried out using the same polymer, same fineness and same spinning conditions as in Example 1. The center-to-center distance L A is set to 1 mm, the center-to-center distance L B is set to 1 mm, and the center-to-center distance L AB is set to 1.5 mm. The first discharge holes 1 and the second discharge holes 4 of the lowermost layer distribution plate 5 are arranged such that the center-to-center distance L AB is 1.5 times the center-to-center distance L A , and the center-to-center distance L AB is 1.5 times the center-to-center distance L B . As described in Table 1, the average deviation rate of the interface shape of the fiber cross section was 15%, resulting that there was a cross section defect.[Comparative Example 2]
[0064] Using the same composite spinneret 18 as in Example 1 except that the arrangement of the discharge holes of the lowermost layer distribution plate 5 is different, spinning was carried out using the same polymer, same fineness and same spinning conditions as in Example 1. The center-to-center distance L A is set to 1 mm, the center-to-center distance L B is set to 1 mm, and the center-to-center distance L AB is set to 1 mm. The first discharge holes 1 and the second discharge holes 4 of the lowermost layer distribution plate 5 are arranged such that the center-to-center distance L AB is 1.0 times the center-to-center distance L A , and the center-to-center distance L AB is 1.0 times the center-to-center distance L B . As described in Table 1, the average deviation rate of the interface shape of the fiber cross section was 35%, resulting that there was a cross section defect.[Comparative Example 3]
[0065] Using the same composite spinneret 18 as in Example 1 except for using the lowermost layer distribution plate 5C, spinning was carried out using the same polymer, same fineness and same spinning conditions as in Example 1. The lowermost layer distribution plate 5C is arranged in a staggered arrangement equivalent to that in Example 3. The number of the first discharge holes 1 per composite fiber is 40, and the number of the second discharge holes 4 per composite fiber is 30. The center-to-center distance L A is set to 1 mm, the center-to-center distance L B is set to 1 mm, and the center-to-center distance L AB is set to 1.6 mm. The first discharge holes 1 and the second discharge holes 4 of the lowermost layer distribution plate 5C are arranged such that the center-to-center distance L AB is 1.6 times the center-to-center distance L A , and the center-to-center distance L AB is 1.6 times the center-to-center distance L B . As described in Table 1, the average deviation rate of the interface shape of the fiber cross section was 18%, resulting that there was a cross section defect. The ratio of the discharge amount of the second polymer component discharged from one second discharge hole 4 to the discharge amount of the first polymer component discharged from one first discharge hole 1 was about 0.13.
[0066] The results of Examples and Comparative Examples are summarized in Table 1. Table 1Example 1Example 2Example 3Example 4Comparative Example 1Comparative Example 2Comparative Example 3(Center-to-center distance L AB between discharge hole 1a and discharge hole 4b) / (Center-to-center distance L A between discharge hole 1a and discharge hole 1b)2.52.52.32.61.51.01.6(Center-to-center distance L AB between discharge hole 1a and discharge hole 4b) / (Center-to-center distance L B between discharge hole 4b and discharge hole 4c)2.52.52.32.61.51.01.6Whether discharge hole 1a and discharge hole 1b are arranged at line-symmetric positions with respect to center line between respective rows of discharge hole 1a and discharge hole 4bArranged at line-symmetric positionsArranged at line-symmetric positionsNot arranged at line-symmetric positionsNot arranged at line-symmetric positionsArranged at line-symmetric positionsArranged at line-symmetric positionsNot arranged at line-symmetric positions(Discharge amount of second polymer component discharged from one discharge hole 4) / (Discharge amount of first polymer component discharged from one discharge hole 1)0.130.400.250.130.130.130.13Average deviation rate [%]1.31.01.82.915.035.018.0Presence or absence of cross section defect of composite fiberAbsentAbsentAbsentAbsentPresentPresentPresent Industrial Applicability
[0067] The present invention can be applied not only to composite spinnerets used in a common solution spinning method, but also to those used in a melt blowing method and a spunbonding method and further to spinnerets used in a wet spinning method and a dry-wet spinning method; however, its application range is not limited to these.Reference Signs List
[0068] 1 FIRST DISCHARGE HOLE 1a ARBITRARY FIRST DISCHARGE HOLE 1b FIRST DISCHARGE HOLE ADJACENT TO DISCHARGE HOLE 1a AT SHORTEST CENTER-TO-CENTER DISTANCE WITH RESPECT TO DISCHARGE HOLE 1a 4b SECOND DISCHARGE HOLE ADJACENT TO DISCHARGE HOLE 1a AT SHORTEST CENTER-TO-CENTER DISTANCE WITH RESPECT TO DISCHARGE HOLE 1a 4c SECOND DISCHARGE HOLE ADJACENT TO DISCHARGE HOLE 4b AT SHORTEST CENTER-TO-CENTER DISTANCE WITH RESPECT TO THE DISCHARGE HOLE 4b 4 SECOND DISCHARGE HOLE 5, 5A, 5B, 5C, 5' LOWERMOST LAYER DISTRIBUTION PLATE 6 DISTRIBUTION PLATE 7 DISTRIBUTION HOLE 8 DISTRIBUTION GROOVE 10 DISCHARGE PLATE 11 DISCHARGE INTRODUCTION HOLE 12 FLOW CONTRACTING HOLE 13 FIRST POLYMER COMPONENT 14 SECOND POLYMER COMPONENT 15 SPIN PACK 16 SPIN BLOCK 17 COOLING APPARATUS 18 COMPOSITE SPINNERET 19 VIRTUAL CIRCLE 20, 20A, 20B, 20C COMPOSITE FIBER 21 SPINNERET DISCHARGE HOLE
Claims
1. A composite spinneret for discharging a composite polymer stream composed of two or more-component polymers, the composite spinneret comprising: at least one distribution plate in which distribution holes and / or distribution grooves for distributing respective polymer components are formed; a lowermost layer distribution plate that is arranged on a downstream side of the distribution plate in a polymer spinning path direction and in which a plurality of first discharge holes for discharging a first polymer component and a plurality of second discharge holes for discharging a second polymer component different from the first polymer component are formed; and a discharge plate arranged on a downstream side of the lowermost layer distribution plate in the polymer spinning path direction and having a spinneret discharge hole for forming a composite polymer stream in which the first polymer component and the second polymer component join with each other, wherein in the first discharge holes and the second discharge holes, all of the first discharge holes which satisfy the following condition 1 and all of the second discharge holes which satisfy the following condition 1 are configured to satisfy the following condition 2, condition 1: the first discharge holes and the second discharge holes for respectively discharging the first polymer component and the second polymer component sandwich an interface in a range forming either a straight line or a smooth curve of an interface between the first polymer component and the second polymer component in a cross section of the composite polymer stream in a direction perpendicular to the polymer spinning path direction, and condition 2: an arbitrary first discharge hole is defined as a discharge hole 1a, a first discharge hole adjacent to the first discharge hole 1a at a shortest center-to-center distance with respect to the first discharge hole 1a is defined as a discharge hole 1b, a second discharge hole adjacent to the discharge hole 1a at a shortest center-to-center distance with respect to the discharge hole 1a is defined as a discharge hole 4b, a second discharge hole adjacent to the discharge hole 4b at a shortest center-to-center distance with respect to the discharge hole 4b is defined as a discharge hole 4c, and a center-to-center distance LAB between the discharge hole 1a and the discharge hole 4b is twice or more a center-to-center distance LA between the discharge hole 1a and the discharge hole 1b and is twice or more a center-to-center distance LB between the discharge hole 4b and the discharge hole 4c.
2. The composite spinneret according to claim 1, wherein all of the first discharge holes which satisfy the condition 1 are arranged to be aligned on either a straight line or a smooth curve, and all of the second discharge holes which satisfy the condition 1 are arranged to be aligned on either a straight line or a smooth curve.
3. The composite spinneret according to claim 2, wherein the first discharge holes which satisfy the condition 1 and the second discharge holes which satisfy the condition 1 are arranged at line-symmetric positions with respect to a center line between a row of the first discharge holes which satisfy the condition 1 and a row of the second discharge holes which satisfy the condition 1.
4. A method for manufacturing a composite fiber, comprising manufacturing a composite fiber by a composite spinning machine using the composite spinneret according to any one of claims 1 to 3.
5. The method for manufacturing a composite fiber according to claim 4, wherein a ratio of a discharge amount of the second polymer component discharged from one of the second discharge holes to a discharge amount of the first polymer component discharged from one of the first discharge holes is 0.3 or more and 3.3 or less.
6. The method for manufacturing a composite fiber according to claim 4, wherein a ratio of a melt viscosity of the first polymer component to a melt viscosity of the second polymer component is 0.2 or more and 5.0 or less.