Spinning apparatus and spinning method

A spinning apparatus includes a spinning cabinet extending in a vertical direction, a spinneret that includes a plurality of spinneret holes, is disposed on an upper end side of the spinning cabinet, and is configured to extrude a spinning dope from the plurality of spinneret holes into an interior space of the spinning cabinet, a first gas supply path connected to the spinning cabinet is configured to supply a first gas from above the spinneret to the interior space, allowing the first gas to come into contact with the spinning dope extruded from the plurality of spinneret holes, and a second gas supply path connected to the spinning cabinet is configured to supply a second gas having a higher temperature than that of the first gas from below the spinneret to the interior space, allowing the second gas to come into contact with the spinning dope extruded from the plurality of spinneret holes.

BACKGROUND OF THE INVENTION

Technical Field

The present inventions relate to a spinning apparatus and a spinning method.

Description of the Related Art

A spinning apparatus, as disclosed in Japanese Published Application JP H9-501989, for example, includes a spinneret in which a plurality of spinneret holes are formed, and a spinning cabinet extending in a vertical direction with the spinneret disposed on an upper end side of the spinning cabinet. When spinning is performed by the spinning apparatus, for example, a spinning dope containing a filament raw material component and a volatile (solvent) component is extruded into the spinning cabinet from the spinneret holes of the spinneret. The spinning dope is dried by coming into contact with a gas supplied into the spinning cabinet. In this way, a plurality of filaments (single fibers) are spun. The plurality of filaments are bundled into yarn, wound onto a godet roller, and then transported in a predetermined direction.

SUMMARY OF THE INVENTION

With regard to a spinning apparatus, it has been desired to reduce production costs by improving the efficiency of spinning. Examples of methods for improving spinning efficiency include a method of improving draft, which is defined as a ratio of a winding speed of the godet roller to an extrusion speed of the spinning dope from the spinneret hole. Nevertheless, simply increasing the winding speed relative to the extrusion speed may make it difficult to improve the draft due to the occurrence of filament breakage in the spinning cabinet.

Therefore, an object of the present invention is to make it possible to improve spinning efficiency in a spinning apparatus by preventing filament breakage that occurs in a spinning cabinet.

One of the causes of filament breakage in the spinning cabinet when trying to improve the draft is presumably that, immediately after the spinning dope is extruded from the spinneret, the volatile component of the spinning dope is volatilized rapidly by the gas supplied into the spinning cabinet, making it difficult to draw the spinning dope.

With regard to this problem, it was found that, when a supply amount per unit time of the gas supplied into the spinning cabinet is simply reduced or a temperature of the gas supplied into the spinning cabinet is simply reduced, the spinning dope is not sufficiently dried, and streams of the spinning dope extruded from the plurality of spinneret holes in the spinning cabinet come into contact with each other due to filament sway, resulting in the occurrence of filament breakage.

At least one of the present inventions is based on such knowledge, and improves the ability to draw a spinning dope well, immediately after being extruded from spinneret holes, and dry the spinning dope while preventing filament breakage caused by contact between a plurality of streams of the spinning dope in the spinning cabinet.

That is, a spinning apparatus according to an embodiment includes a spinning cabinet extending in a vertical direction, a spinneret that includes a plurality of spinneret holes, is disposed on an upper end side of the spinning cabinet, and is configured to extrude a spinning dope from the plurality of spinneret holes into an interior space of the spinning cabinet. A first gas supply path can be connected to the spinning cabinet and configured to supply a first gas from above the spinneret to the interior space, allowing the first gas to come into contact with the spinning dope extruded from the plurality of spinneret holes. A second gas supply path can be connected to the spinning cabinet and configured to supply a second gas having a higher temperature than that of the first gas from below the spinneret to the interior space, allowing the second gas to come into contact with the spinning dope extruded from the plurality of spinneret holes.

According to the configuration described above, the spinning dope immediately after being extruded from the spinneret holes, comes into contact with the first gas supplied by the first gas supply path from above the spinneret, and thus is dried relatively slowly. As a result, the spinning dope immediately after being extruded from the spinneret holes, is prevented from drying rapidly, the spinning dope can be drawn while preventing filament breakage, and thus the draft can be improved.

Further, by contacting the spinning dope extruded from the spinneret holes with the second gas supplied by the second gas supply path from below the spinneret, drying is promoted. As a result, the spinning dope can be dried while preventing the occurrence of filament breakage caused by a plurality of streams of the spinning dope coming into contact with each other during drying in the spinning cabinet. Further, the second gas can be supplied to the interior space of the spinning cabinet separately from the first gas, making it possible to more easily control the temperatures and supply amounts of the first gas and the second gas individually. Thus, the spinning efficiency can be improved.

The spinning apparatus may further include a third gas supply path connected to the spinning cabinet, below a position at which the second gas is supplied to the spinning cabinet, and configured to supply a third gas to the interior space, allowing the third gas to come into contact with the spinning dope extruded from the plurality of spinneret holes. As a result, the spinning dope dried to a certain degree by the second gas can be further dried by the third gas supplied from the third gas supply path.

The spinning cabinet may include a gas discharge port configured to discharge gas from the interior space to outside the spinning cabinet. The gas discharge port may be disposed between the position at which the second gas is supplied to the spinning cabinet and a position at which the third gas is supplied to the spinning cabinet.

As a result, in the interior space of the spinning cabinet, the third gas can be made to flow upward from below, from the position at which the third gas is supplied toward a position of the gas discharge port. As such, a gas having a low volatile component concentration can be brought into contact with the spinning dope transported through the interior space to efficiently dry the spinning dope.

The first gas supply path may be configured to supply the first gas in a longitudinal direction of the spinning cabinet, from above the spinneret toward below the spinneret. As a result, the spinning dope can be slowly dried by the first gas while preventing streams of the spinning dope immediately after being extruded from each of the spinneret holes from coming into contact with each other due to the occurrence of filament sway caused by the first gas, and thus the draft can be improved.

Further, a spinning method according to another embodiment includes disposing a spinneret including a plurality of spinneret holes on an upper end side of a spinning cabinet extending in a vertical direction, extruding a spinning dope from the plurality of spinneret holes into an interior space of the spinning cabinet, supplying a first gas from above the spinneret to the interior space, allowing the first gas to come into contact with the spinning dope passing through the plurality of spinneret holes, and supplying a second gas having a higher temperature than that of the first gas from below the spinneret to the interior space, allowing the second gas to come into contact with the spinning dope extruded from the plurality of spinneret holes.

The spinning method may further include supplying a third gas to the interior space, below a position at which the second gas is supplied to the spinning cabinet, allowing the third gas to come into contact with the spinning dope extruded from the plurality of spinneret holes.

A gas may be discharged from the interior space to outside the spinning cabinet, vertically between the position at which the second gas is supplied to the spinning cabinet and a position at which the third gas is supplied to the spinning cabinet.

The first gas may be supplied from above the spinneret toward below the spinneret.

In at least some embodiments, spinning efficiency can be improved in a spinning apparatus by reducing or preventing filament breakage that occurs in a spinning cabinet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Embodiments are described below with reference to the drawings.FIG. 1is a general, schematic view of a spinning apparatus1according to an embodiment. The spinning apparatus1, as an example, spins a filament F of a cellulose acetate fiber by dry spinning.

The spinning apparatus1includes a mixing device2, a filtration device3, a spinning cabinet4, a spinneret5, a first gas supply path R1, a second gas supply path R2, a third gas supply path R3, a gas discharge path R4, a diffuser6, an oil agent impregnating unit7, a godet roller8, and guide members9,10. Although not illustrated inFIG. 1, the spinning apparatus1of the present embodiment includes a plurality of the spinning cabinets4, and the supply paths R1to R3are branched and connected to each of the spinning cabinets4.

The mixing device2mixes a spinning dope D. The spinning dope D includes a raw material component of the filament F and a volatile component. As an example, the raw material component of the filament F is cellulose acetate and the volatile component is acetone. The filtration device3filters the spinning dope D mixed by the mixing device2.

The spinning cabinet4extends in a vertical direction. In the spinning cabinet4, a first gas supply port4a, a second gas supply port4b, a third gas supply port4c, a gas discharge port4d, and a filament transport port4eare provided spaced apart from each other in a longitudinal (vertical) direction of the spinning cabinet4. Of these, the second gas supply port4b, the third gas supply port4c, and the gas discharge port4dare disposed on a side portion of the spinning cabinet4.

The first gas supply port4ais disposed on an upper end of the spinning cabinet4and is connected to the first gas supply path R1. The second gas supply port4bis disposed below a lower end of the spinneret5and is connected to the second gas supply path R2. The third gas supply port4cis disposed below the second gas supply port4band is connected to the third gas supply path R3.

The gas discharge port4dis disposed vertically between a position at which the second gas is supplied to the spinning cabinet4and a position at which the third gas is supplied to the spinning cabinet4(in other words, vertically between the second gas supply port4band the third gas supply port4c), and discharges a gas from an interior space S to outside the spinning cabinet4. The gas discharge port4dis connected to the gas discharge path R4. The filament transport port4eis disposed at a lower end of the spinning cabinet4, and transports the filament F spun in the spinning cabinet4to outside the spinning cabinet4.

As a specific example, the second gas supply port4bis disposed above a center of the spinning cabinet4in the longitudinal direction. Further, as an example, the second gas supply port4bis disposed at a position below a center position P1between the upper end of the spinning cabinet4and an upper end of the gas discharge port4d. An upper end of the second gas supply port4bis positioned below the lower end of the spinneret5. The upper end of the second gas supply port4bis preferably disposed at a position downward from the upper end of the spinning cabinet4at a distance within a range of not less than 20% and not greater than 30% of a length dimension of the spinning cabinet4.

Further, the gas discharge port4dis disposed below the center of the spinning cabinet4in the longitudinal direction. As an example, the gas discharge port4dis disposed at a position overlapping with a center position P2between a lower end of the second gas supply port4band an upper end of the third gas supply port4c. Thus, at least a portion of the gas discharge port4dcan be positioned below the center position P2.

Further, a length dimension from the upper end of the spinning cabinet4to the upper end of the gas discharge port4dis longer than a length dimension from the lower end of the second gas supply port4bto the upper end of the third gas supply port4cof the spinning cabinet4. Further, a length dimension from the upper end of the spinning cabinet4to the upper end of the second gas supply port4bis longer than a length dimension from the lower end of the spinning cabinet4to a lower end of the third gas supply port4c.

The spinneret5includes a plurality of spinneret holes5a, and is disposed on the upper end side of the spinning cabinet4. The spinneret5extrudes the spinning dope D from the spinneret holes5ainto the interior space S of the spinning cabinet4. The spinning apparatus1pressurizes the spinning dope D by a pump11, and extrudes the spinning dope D from the spinneret holes5a. An extrusion speed V1at which the spinning dope D is extruded from the spinneret holes5ais set by adjusting the pump11.

The first gas supply path R1is connected to the spinning cabinet4, and supplies a first gas to the interior space S from above the spinneret5, allowing the first gas to come into contact with the spinning dope D extruded from the spinneret holes5a. In the present embodiment, the first gas supply port4aof the spinning cabinet4connected to the first gas supply path R1is disposed above the spinneret5in the interior space S of the spinning cabinet4. As a result, the first gas supply path R1is disposed capable of supplying the first gas in the longitudinal direction of the spinning cabinet4, from above the spinneret5toward below the spinneret5. As an example, a temperature of the first gas supplied to the interior space S is set to a value within a range of not less than 60° C. and not greater than 70° C.

The second gas supply path R2is connected to the spinning cabinet4, and supplies a second gas having a higher temperature than the first gas to the interior space S from below the spinneret5, allowing the second gas to come into contact with the spinning dope D extruded from the spinneret holes5a. In the present embodiment, the second gas supply path R2is configured to supply the second gas to the interior space S of the spinning cabinet4, from the side of the spinning cabinet4. A temperature of the second gas supplied to the interior space S is, as an example, higher than 70° C., and herein is set to a value within a range of not less than 90° C. and not greater than 95° C.

Further, as an example, a supply amount of the second gas to the interior space S per unit time, which can be referred to as a gas supply rate, is set to a value equal to or greater than a supply amount of the first gas to the interior space S per unit time, which can also be referred to as a gas supply rate. As an example, the supply amount of the second gas to the interior space S per unit time is set to a value within a range of not less than 100% and not greater than 143% of the supply amount of the first gas to the interior space S per unit time.

The third gas supply path R3is connected to the spinning cabinet4, below the position at which the second gas is supplied to the spinning cabinet4, and is configured to supply a third gas to the interior space S, allowing the third gas to come into contact with the spinning dope D extruded from the spinneret holes5a. In the present embodiment, the third gas supplied to the interior space S has a higher temperature than the first gas. Further, the third gas supply path R3is configured to supply the third gas to the interior space S of the spinning cabinet4, from the side of the spinning cabinet4. The third gas may have a temperature higher than the second gas or may have a temperature lower than the second gas. Here, the first to third gases are drying gases for drying the spinning dope D and are all, as an example, air.

The discharge path R4is connected to the spinning cabinet4, vertically between the position at which the second gas is supplied to the spinning cabinet4and the position at which the third gas is supplied to the spinning cabinet4, and discharges a gas from the interior space S of the spinning cabinet4.

The diffuser6supplies the second gas supplied to the interior space S of the spinning cabinet4to an inner side of the spinning cabinet4in a radial direction while diffusing the second gas below the spinneret5. The diffuser6is a cylindrical body, and is disposed in the interior space S with a cylinder axial direction thereof aligned with the longitudinal direction of the spinning cabinet4. A plurality of openings6aare formed in a circumferential surface of the diffuser6. The second gas, by passing through the openings6aof the diffuser6, is supplied to an inner side of the diffuser6in the radial direction while being diffused.

Note that, in a case where the second gas is sufficiently diffused in the interior space S without use of the diffuser6or the like, the diffuser6may be omitted. The oil agent impregnating unit7impregnates the spun filament F with a fiber oil agent (as an example, a fiber oil agent emulsion).

The godet roller8is rotatably supported about a roller axis thereof. The godet roller8comes into contact with the filament F at a circumferential surface thereof while being rotated by a driving force transmitted from a drive device12, thereby transporting the filament F toward the guide members9,10. A rotation speed (winding speed) V2of the godet roller8is adjusted by the drive device12.

In the spinning apparatus1, a draft V2/V1is adjusted by adjusting the speeds V1, V2individually. The draft V2/V1can be set as appropriate. However, with the draft V2/V1set to a value greater than 1.0, the spinning dope D extruded from the spinneret holes5aof the spinneret5is drawn in a transport direction. In the present embodiment, the draft V2/V1is set to a value greater than 1.0 as an example. The guide members9,10guide the filament F transported from the godet roller8in a predetermined direction.

In a spinning method of the present embodiment, spinning is performed using the spinning apparatus1having the configuration described above. That is, the spinneret5is disposed on the upper end side of the spinning cabinet4, the spinning dope D is extruded from the spinneret holes5ainto the interior space S of the spinning cabinet4, and the first gas is supplied from above the spinneret5to the interior space S, allowing the first gas to come into contact with the spinning dope D passing through the spinneret holes5a.

Further, the second gas having a higher temperature than the first gas is supplied to the interior space S from below the spinneret5, allowing the second gas to come into contact with the spinning dope D extruded from the spinneret holes5a. As an example, the first gas is supplied from above the spinneret5toward below the spinneret5.

Further, the third gas is supplied to the interior space S, below the position at which the second gas is supplied to the spinning cabinet4, allowing the third gas to come into contact with the spinning dope D extruded from the spinneret holes5a. Further, a gas is discharged from the interior space S to outside the spinning cabinet4, vertically between the position at which the second gas is supplied to the spinning cabinet4and the position at which the third gas is supplied to the spinning cabinet4.

For example, when the spinning apparatus1is driven, the spinning dope D that has passed through the mixing device2and the filtration device3is extruded downward from above, from the spinneret holes5aof the spinneret5toward the interior space S of the spinning cabinet4, by the driving force of the pump11. Further, the first gas is supplied from the first gas supply path R1to the interior space S of the spinning cabinet4via the first gas supply port4a.

The temperature of the first gas supplied to the interior space S is set lower than the temperature of the second gas supplied to the interior space S so that the spinning dope D immediately after being extruded from the spinneret holes5ais slowly dried. Accordingly, the volatile component of the spinning dope D is partially volatilized by the first gas immediately after the spinning dope D is extruded from the spinneret holes5a, but remains in the spinning dope D to the extent that the spinning dope D is drawn in accordance with the value of the draft V2/V1set in advance. As a result, in the spinning apparatus1, the spinning dope D extruded from the spinneret holes5ais stably drawn in the transport (vertical) direction while being slowly dried by the first gas.

Here, a diameter of the spinning dope D extruded from the spinneret holes5abecomes narrower when the winding speed V2is increased while the supply amount of the spinning dope D to the spinneret5is kept constant. Then, it becomes impossible to stably wind the filament F spun from the spinning dope D by the godet roller8. The ratio V2/V1at which stable winding with the godet roller becomes impossible is defined as the “maximum draft”.

In the present embodiment, the spinning dope D immediately after being extruded from the spinneret holes5acan be stably drawn, making it possible to increase the maximum draft V2/V1. As a result, for example, the maximum draft V2/V1can be increased when the winding speed V2is set to be equivalent to that in the related art can be increased, and the maximum draft V2/V1can be prevented from decreasing even when the winding speed V2is set to a speed higher than that in the related art.

Further, the second gas is supplied from the second gas supply path R2to the interior space S via the second gas supply port4b. The second gas comes into contact with the spinning dope D while being diffused by the diffuser6in the interior space S. With the second gas having a higher temperature than the first gas, the spinning dope D comes into contact with the second gas, thereby promoting the volatilization of the volatile component of the spinning dope D.

When the volatilization of the volatile component of the spinning dope D progresses to a certain degree, a skin layer is formed on the spinning dope D, and the spinning dope D solidifies to form the filament F. In the present embodiment, the second gas having a higher temperature than the first gas is brought into contact with the spinning dope D to promote volatilization of the volatile component of the spinning dope D, and thus a plurality of the filaments F can be favorably formed while preventing a plurality of streams of the spinning dope D extruded from the plurality of spinneret holes5afrom coming into contact with each other by the gas flowing through the interior space S and breaking (breaking by filament sway).

Further, the third gas is supplied from the third gas supply path R3to the interior space S via the third gas supply port4c. In the spinning cabinet4, the gas discharge port4dis disposed above the third gas supply port4c, and thus the third gas flows upward through the interior space S from below, from the second gas supply port4btoward the gas discharge port4d.

Therefore, the filament F being transported can come into contact with the third gas in a state in which the volatile component concentration is relatively low by counterflow drying in the interior space S, thereby further promoting drying. The first to third gases containing the volatile component are discharged from the gas discharge port4dto outside the spinning cabinet4, flow through the discharge path R4, and are subsequently collected.

Here, in the interior space S, the first gas flows downward from above, the second gas is mixed with the first gas, and the mixture flows downward from above. As an example, a region between the second gas supply port4band the gas discharge port4dof the interior space S includes a region in the interior space S where a flow rate of the gas is highest. Further, as an example, a region between the upper end of the spinning cabinet4in the interior space S and the second gas supply port4bincludes a region in the interior space S where the flow rate of the gas is lowest.

The filament F transported from the filament transport port4eof the spinning cabinet4is bundled into a yarn Y. The yarn Y is impregnated with the fiber oil agent by the oil agent impregnating unit7, and subsequently wound by the godet roller8. The yarn Y travels around the circumferential surface of the godet roller8, and is subsequently transported in a predetermined direction while being guided by the guide members9,10.

Note that the third gas supply port4cis disposed below the gas discharge port4das an example, but may be disposed below the second gas supply port4band above the gas discharge port4d. Further, in a case where the volatilization of the volatile component of the spinning dope D can be sufficiently performed by the first and second gases, the third gas supply port4cand the third gas supply path R3may be omitted. Further, in a case where the third gas is not used or the like, the gas discharge port4dand the discharge path R4may be omitted.

As described above, in the present embodiment, the spinning dope D immediately after being extruded from the spinneret holes5acomes into contact with the first gas supplied by the first gas supply path R1from above the spinneret5, thereby being dried relatively slowly. As a result, the spinning dope D immediately after being extruded from the spinneret holes5ais prevented from drying rapidly, the spinning dope D can be drawn while preventing filament breakage, and thus the draft V2/V1can be improved.

Further, the spinning dope D extruded from the spinneret holes5acomes into contact with the second gas supplied by the second gas supply path R2from below the spinneret5, thereby promoting drying. As a result, the spinning dope D can be dried while preventing the occurrence of filament breakage caused by a plurality of streams of the spinning dope D coming into contact with each other during drying in the spinning cabinet4. Further, the second gas can be supplied to the interior space S of the spinning cabinet4separately from the first gas, making it possible to easily control the temperatures and supply amounts of the first gas and the second gas individually. Thus, the spinning efficiency can be improved.

Further, the spinning apparatus1includes the third gas supply path R3, and thus the spinning dope D dried to a certain degree by the second gas can be further dried by the third gas supplied from the third gas supply path R3.

Further, the gas discharge port4dof the spinning cabinet4is disposed between the position at which the second gas is supplied to the spinning cabinet4and the position at which the third gas is supplied to the spinning cabinet4, and thus, in the interior space S of the spinning cabinet4, the third gas can be made to flow upward from below, from the position at which the third gas is supplied toward the position of the gas discharge port4d, and a gas having a low volatile component concentration can be brought into contact with the spinning dope D transported through the interior space S to efficiently dry the spinning dope D.

Further, the first gas supply path R1is disposed so as to be capable of supplying the first gas in the longitudinal direction of the spinning cabinet4from above the spinneret5toward below the spinneret5, and thus the spinning dope D can be slowly dried by the first gas while preventing streams of the spinning dope D immediately after being extruded from each of the spinneret holes5afrom coming into contact with each other due to the occurrence of filament sway caused by the first gas, and the draft V2/V1can be improved.

Relationship Between Winding Speed V2of Godet Roller8and Maximum Draft V2/V1

FIG. 2is a graph showing a relationship between the winding speed V2of the godet roller8and the maximum draft V2/V1.FIG. 2shows the relationship between the winding speed V2of the godet roller8and the maximum draft V2/V1when, using the spinning apparatus1with the first gas supply port4aclosed and the position of the second gas supply port4bchanged to a lateral position of the spinning cabinet4overlapping with the spinneret5, the filament F is spun by setting the temperature of the second gas supplied to the interior space S and the supply amount of the second gas to the interior space S per unit time to different values. The spinneret5was configured to include 100 of the spinneret holes5a, each having a triangular shape.

InFIG. 2, settings A to C are configured to have equivalent supply amounts of the second gas to the interior space S per unit time, and the temperatures of the second gas supplied to the interior space S become lower in the order of A, B, and C. Settings C to E are configured to have equivalent temperatures of the second gas supplied to the interior space S, and the supply amounts of the second gas to the interior space S per unit time become smaller in the order of the settings C, D, E.

As shown inFIG. 2, for any of the settings A to E, when the winding speed V2increases, the maximum draft V2/V1decreases. This is thought to be because, for example, a tension acting in the transport direction on the spinning dope D extruded from the spinneret holes5aincreases, which makes it easy for filament breakage to occur.

Further, in any of the settings A to E, when the temperature of the second gas supplied to the interior space S rises, the maximum draft V2/V1decreases. This is thought to be because, for example, the spinning dope D immediately after being extruded from the spinneret holes5ais rapidly dried by the second gas having a relatively high temperature and becomes difficult to draw, which makes it easy for filament breakage to occur.

Further, even when the temperature of the second gas supplied to the interior space S and the winding speed V2are equivalent as indicated by the settings C and D, the maximum draft V2/V1decreases when the supply amount of the second gas to the interior space S per unit time is large. This is thought to be because, for example, the spinning dope D immediately after being extruded from the spinneret holes5ais rapidly dried by a relatively large amount of the second gas and becomes difficult to draw, which makes it easy for filament breakage to occur.

In contrast, in the spinning apparatus1according to the present embodiment, the spinning dope D immediately after being extruded from the spinneret holes5ais slowly dried by the first gas having a lower temperature than the second gas, thereby facilitating the drawing of the spinning dope D in the transport direction and, as a result, making it possible to improve the maximum draft V2/V1at a winding speed V2equivalent to that in the related art. Thus, even in a case where the winding speed V2is increased, a reduction of the maximum draft V2/V1can be suppressed compared to the related art. Accordingly, filament breakage that occurs in the spinning cabinet4is prevented, making it possible to improve the spinning efficiency.

Confirmation Test

The spinning cabinet4illustrated inFIG. 1was fabricated as an example. Further, a spinning cabinet having a same configuration with the example except that the first gas supply port4aof the spinning cabinet4was closed and the position of the second gas supply port4bwas changed to a lateral position of the spinning cabinet4overlapping with the spinneret5was fabricated as a comparative example.

The same spinneret5was disposed on the upper ends of the spinning apparatuses of the example and the comparative example, and spinning was performed using the same spinning dope D. As a result, in the example, insufficient drying of the spinning dope D after extrusion from the spinneret holes5awas suppressed to the same extent as in the comparative example, and the winding speed V2could be increased by approximately 23.7% compared to the comparative example while keeping the maximum draft V2/V1at a constant value. Thus, in this example, it was found that the maximum draft V2/V1is easily improved compared to the comparative example.

Furthermore, according to another study by the inventors of the present application, it was found that, as the position of the gas discharge port4dis moved to the lower side of the spinning cabinet4between the second gas supply port4band the third gas supply port4c, the filament sway of the spinning dope D caused by the second gas is less likely to occur, and the maximum draft V2/V1is easily improved. Nevertheless, it was also found that, as the position of the gas discharge port4dis moved to the lower side of the spinning cabinet4, the drying of the spinning dope D becomes more likely to be delayed. Thus, it is considered preferable to dispose the gas discharge port4din an appropriate position in the spinning cabinet4in accordance with the raw material component of the filament F to be spun, a filament denier (FD), the speeds V1, V2, and the like.

Further, it was found that, as the position of the second gas supply port4bis moved to the upper side of the spinning cabinet4, the drying of the spinning dope D transported through the interior space S can be promoted by the second gas, thereby tending to prevent filament breakage due to contact between the plurality of streams of the spinning dope D. Thus, it is considered preferable to dispose the position of the second gas supply port4bon the upper side of the spinning cabinet4within a range in which the spinning dope D can be slowly dried by the first gas.

The present inventions are not limited by the embodiments disclosed above, and the configurations and the methods of these embodiments can be changed, added, or deleted, without departing from the spirit of the present inventions.

As described above, the present inventions have excellent effects of improving spinning efficiency in a spinning apparatus by preventing filament breakage that occurs in a spinning cabinet. It is thus advantageous to widely apply one or more of the present inventions to spinning apparatuses that can exhibit the significance of this effect.