JPH11256420A - Spinning pack for melt spinning - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spinning pack for melt spinning that can reduce the unevenness in filament fineness and the polymer deterioration. SOLUTION: This spinning pack has the inflow block 2, the straightening vane 3 and the spinneret 6 built-in in the polymer flow direction and a plurality of the straightening orifices 3a bored on the straightening vane 3 are allowed to have the squeezed zone 3ad. In addition, it is characterized by that space areas 9, 10 are provided on the inflow face and the outflow face of the vane 3 and no granular filtration medium is employed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melt spinning die pack used in a synthetic fiber manufacturing process.

[0002]

2. Description of the Related Art Conventionally, a spinning spinneret pack used in a synthetic fiber manufacturing process generally has, for example, a structure shown in FIG. The melt spinning die pack includes a spinneret 6 having a large number of spinning holes 6a, a pressure plate 5 having a large number of holes,
2 are laminated with a wire mesh filter 13 supporting the filter 2, an encapsulation layer of the particulate filter medium 12, a spacer 11 forming the encapsulation layer, and an inflow block 2 having an inflow hole for molten polymer, and finally the inflow block 2 is screwed through a screw portion 2 a. It is screwed into the screw portion 1a at the top of the pack case 1 and is fixed by tightening. Stainless steel particles, glass balls, quartz particles, and the like are weighed and sealed in the granular filter medium 12.

[0003] However, since the granular filter medium 12 has fluidity, in handling during the transportation process after assembling the melt-spinning spinneret pack and mounting it on the spinning machine, the spinneret pack is inclined or subjected to impact or vibration. , The thickness of the filter layer of the granular filter medium 12 may be uneven. A die pack having a thickness unevenness in the filtration layer as described above,
When the melt spinning is performed by directly attaching to the spinning machine, the high-pressure molten polymer locally concentrates on the thin portion of the filtration layer, and the concentrated portion tends to gradually increase uneven distribution over time. Was. As a result, there is a problem that the filtered molten polymer has a non-uniform flow distribution in each of the spinning holes of the spinneret 6, resulting in unevenness in fineness between the spun filaments.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to make the polymer flow in the spin pack uniform and shorten the residence time.
It is an object of the present invention to provide a melt spinning die pack capable of reducing unevenness of fineness and deterioration of a polymer.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a melt-spinning die pack in which an inflow block, a flow straightening plate and a spinning die are sequentially incorporated in a polymer flowing direction. And a space portion is provided on each of an inflow surface and an outflow surface of the rectifying plate, and no particulate filter medium is used.

[0006] As described above, a flow resistance is generated in the molten polymer without using a particulate filter medium, which causes an uneven flow of the molten polymer, and by providing a restricting portion in a rectifying hole of the rectifying plate. The resistance allows the molten polymer to be uniformly distributed in both the inflow surface and the outflow surface of the flow straightening plate, thereby enabling the spinning of a yarn having a uniform fineness from a spinneret. Further, since the residence time of the molten polymer is shortened, polymer deterioration can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a melt spinneret pack according to the present invention. The melt spinning die pack includes a spinning die 6 having a large number of spinning holes 6a, a plate-shaped filtration filter 4, a rectifying plate 3 having a large number of rectifying holes 3a, and An inflow block 2 having a molten polymer inflow hole 2c at the center is laminated and inserted, and the uppermost inflow block 2 is screwed into the screw portion 1a at the top of the pack case 1 via the screw portion 2a, and tightened and fixed. ing. When the melt spinning is performed, a high-pressure molten polymer is caused to flow from the inflow hole 2 c of the inflow block 2, passed through the flow straightening plate 3 and the filter 4, and spun into a filament form from the spinning hole 6 a of the spinneret 6.

In general, the melt spinning die pack is provided with a filter medium for capturing foreign substances mixed in the molten polymer and altered substances obtained by gelling the polymer before spinning from the spinning die 6. In the mouthpiece pack, a particulate filter medium is not used, and a plate-shaped filter 4 is used. Although the plate-shaped filtration filter 4 is provided on the downstream side of the current plate 3 in the drawing, it may be provided on at least one of the upstream surface and the downstream surface.

[0009] The plate-shaped filtration filter 4 is not deformed in shape like a filtration layer of a granular filter medium, even if a die pack is inclined or subjected to shock or vibration in a transportation process or the like. . Therefore, the deformation does not cause uneven flow of the polymer in the die pack. As the plate-shaped filtration filter used here, a porous sheet or a plate material such as a wire mesh, a metal fiber nonwoven fabric, a sintered metal plate, and a sintered ceramics plate can be used.

The rectifying plate 3 is provided with a space 9 having a uniform gap thickness on the inflow surface side between the rectification plate 3 and the inflow block 2, and is also provided with a uniform gap thickness between the rectification plate 3 and the filtration filter 4 on the outflow surface side. A space 10 is provided. The space 10 on the outflow surface side has a flat shape, and the space 9 on the inflow surface side forms the inflow surface of the current plate 3 in a conical shape, and the inflow block 2 facing the conical shape.
Are formed in an inverted conical shape to form a conical cylindrical shape.

In the spaces 9 and 10 having the above structure, the molten polymer in the space 9 is evenly distributed to the flow regulating holes 3a.
In the space 10, the distribution is evenly distributed to the spinning holes 6 a. In particular, on the inflow side of the rectifying plate 3, since the number of the inflow holes 2c of the inflow block 2 is one at the center, the distances to the respective rectification holes 3a are different from each other, so that uneven flow is likely to occur. Since the inflow surface of the flow straightening plate 3 is formed in a conical shape and the distance to the outflow surface of each flow straightening hole 3a is adjusted, the flow of the molten polymer can be made substantially uniform.

Further, each of the flow regulating holes 3a of the current regulating plate 3 is provided with a throttle 3ad. Due to the installation of the throttle portion 3ad, the molten polymer flowing into the straightening hole 3a of the straightening plate 3 generates a large flow resistance in the narrowed portion 3ad, and the molten polymer flows between the straightening plate 3 and the inflow block 2 due to the flow resistance. The pressure and the flow rate are distributed uniformly in the space 9. When the molten polymer reaches the space 10 between the straightening plate 3 and the filter 4 after passing through the straightening holes 3a, the pressure and the flow rate are evenly distributed in the space 10 as well.

The molten polymer having a uniform flow rate and pressure as described above passes through the filtration filter 4 while maintaining its state, so that the filament having a uniform thickness is formed from each spinning hole 6a of the spinneret 6. Spun into a yarn with less fiber spots. In order to further exhibit such an effect, it is preferable that the drawing ratio of the drawing portion 3ad (cross-sectional area of the drawing portion / cross-sectional area of the straightening hole body) × 100 is 50% or less, and more preferably 7% or less. It is good to make it 30%. If the drawing ratio is smaller than 7%, the residence time of the molten polymer increases, and the polymer tends to deteriorate.

Further, a large number of rectifying holes 3a in the rectifying plate 3
Are preferably arranged circumferentially with respect to the center of the circular current plate 3, more preferably at least two or more concentric multiple circles. Thus, the rectifying hole 3
a are arranged in a circular shape, the polymer flowing into the circular current plate 3 is converted into a large number of spinning holes 6 a of the circular spinning die 6.
And the flow rate can be made uniform, and the fineness unevenness of the spun yarn can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the structure shown in FIG. 1, a draw ratio of a draw hole of a flow straightening plate of a flow straightening plate is set to 16%, a non-woven fabric filter made of a metal fiber is used as a filter, and a spinneret for melt spinning without using a granular filter medium. A pack (the present invention) was produced. In addition, in the structure shown in FIG. 2, a filtration layer was formed from stainless steel particles as a granular filter material, and a spinneret pack for melt spinning (conventional example) in which straight holes were provided in a pressure plate was manufactured.

Using these two types of melt spinning die packs, nylon 6 is melt-spun and stretched to obtain 70%.
A denier / 24 filament multifilament yarn was produced. The total fineness at this time, the fineness difference (between yarns (d)
And the residence time were evaluated, and the results in Table 1 were obtained.

[0017]

[Table 1]

In Table 1, "first yarn" and "second yarn" are the left yarn (first yarn) and the right yarn (second yarn) of a single-cap, two-thread take-up. Article).

From the results shown in Table 1, the total fineness of the multifilament yarn obtained in the present invention was closer to the target fineness (70 denier) than the total fineness obtained in the conventional example. Also,
The fineness difference from the target fineness (70 denier) was 0.4 d in the present invention, but 2.2 d in the conventional example.
And there was a difference of 5 times or more. Further, the difference in fineness in the yarn was 2.5% in the present invention, and 4.8% in the conventional example, which was about double.

The residence time in the present invention is very short in comparison with the conventional example, and the spinning is spun from the spinneret.

[0021]

As described above, the melt-spinning die pack according to the present invention does not use a particulate filter medium which causes an uneven flow of the molten polymer, and provides a throttle portion in the straightening hole of the straightening plate. As a result, flow resistance is generated in the molten polymer, so that the flow resistance uniformly distributes the molten polymer in both of the inflow surface and the outflow surface of the flow straightening plate. Can be made possible. Further, since the residence time of the molten polymer is shortened, polymer deterioration can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view illustrating a melt spinning die pack of the present invention.

FIG. 2 is a schematic longitudinal sectional view illustrating a conventional melt spinning die pack.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pack case 2 Inflow block 2c Inflow hole 3 Rectifier plate 3a Rectifier hole 3ad Restriction part 4 Plate-shaped filtration filter 6 Spinneret 6a Spinning hole 9,10 Space

Claims (5)

[Claims] An inflow block in the flow direction of the polymer,
In a melt spinning spinneret pack incorporating a straightening plate and a spinneret, a narrow portion is provided in a large number of straightening holes formed in the straightening plate, and a space is provided in each of an inflow surface and an outflow surface of the straightening plate. A melt-spun spinneret pack that does not use granular filter media. 2. The spinning die pack according to claim 1, wherein the squeezing rate of the squeezing portion of the rectifying hole is set to 50% or less. 3. The melt-spinneret pack according to claim 1, wherein an inflow surface of the rectifying plate is formed in a conical shape, and a surface of the inflow block facing the inflow surface of the rectifying plate is formed in an inverted conical shape. . 4. The spinneret pack for melt spinning according to claim 1, wherein the plurality of rectifying holes are arranged circumferentially with respect to the center of the rectifying plate. 5. The melt-spinning die pack according to claim 4, wherein the circumferential arrangement is at least two or more double concentric circles.