JP2003342826A - Spinneret pack and spinning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spinneret pack in which the melt polymer reservoir of a top insert is formed of an upper tilted surface and a lower tilted surface facing the upper tilted surface, and which can eliminate the abnormal stay of a melted polymer in the spinneret pack to prevent the quality deterioration of the melted polymer, and to provide a spinning method. <P>SOLUTION: In a distribution plate 3, the ratio (QI/QC) of a melted polymer extrusion flow rate (QI) per unit area from the innermost circular region to a melted polymer extrusion flow rate (QC) per unit area from the central circular region, and the ratio (QO/QC) of a melted polymer extrusion flow rate (QO) per unit area from the outermost circular region to the melted polymer extrusion flow rate (QC) per unit area from the central circular region are 1.2 to 1.6, respectively. The melted polymer extrusion flow rates per unit area from the central circular region to the innermost circular region and to the outermost circular region are gradually increased, respectively. The diameter and length of each distribution hole 11 are formed so that the loss of pressure becomes 0.7 kg/cm<SP>2</SP>to 50 kg/cm<SP>2</SP>. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spinning pack for an annular nozzle used for spinning multifilaments and staple fibers, and a spinning method. More specifically, the molten polymer reservoir of the top insert is inclined upward. The present invention relates to a spinneret pack formed between a surface and a lower inclined surface facing the surface, and a spinning method using the spinneret pack.

[0002]

2. Description of the Related Art Heretofore, as a spinneret pack of this type, particularly, those used for spinning synthetic fibers,
For example, a structure shown in FIG. 11 is known. Figure 11
The spinneret pack shown in FIG. 1 includes a pack case 1, a top insert 2 having a molten polymer inlet 9 and a molten polymer reservoir 10, and a sand layer 1 for filtering the molten polymer.
2. Holding the sand layer 12 and backing up the filter layer 8 for performing the microfiltration of the molten polymer,
The doughnut-shaped molten polymer reservoir recess 14
A bridge plate 5 having a rectifying hole 13 leading to the core and a spinneret 6 having a spinning hole 15.

Molten polymer reservoir 10 of top insert 2
Is a substantially conical upper inclined surface 10a with which the inflow port 9 communicates.
And a substantially conical lower inclined surface 10b.

The molten polymer flowing into the inlet 9 of the top insert 2 is guided in the outer peripheral direction by the molten polymer reservoir 10 of the top insert 2. When the molten polymer flows through the molten polymer reservoir 10, the molten polymer comes into contact with the upper inclined surface 10a and the lower inclined surface 10b. As a result, the molten polymer flowing near the inner wall surface forming the molten polymer reservoir 10 is deprived of heat by the pack case 1 and the bridge plate 5 to lower the temperature of the molten polymer, thereby increasing the viscosity and increasing the fluidity. The flow velocity decreases due to the decrease and contact friction.

Therefore, the molten polymer flowing from the molten polymer reservoir 10 into the sand layer 12 tends to have a poor flow on the inner peripheral side and the outer peripheral side (see the arrow in FIG. 11), and this tendency tends to occur. Is also maintained in the downstream region (in the example shown, the dispersion plate 13, the spinneret 15),
Abnormal retention of the molten polymer in the spinneret pack 1 occurs.

The molten polymer thus abnormally retained in the spinneret pack 1 is kept at a high temperature of, for example, 280 ° C., and as the residence time becomes longer, it is affected by heat and gels and thermally decomposes. , The molecular weight, the viscosity, and other properties are greatly changed to cause an abnormality in the molten polymer flow in the pack, and the altered molten polymer is discharged from the spinning holes 15 of the nozzle 6 to produce the yarn quality of the fiber. Has a problem in that the fineness between single yarns is large, and the fibers have different chemical and physical characteristics, and the yarn breakage rate becomes high.

Among the above problems, regarding the single yarn fineness unevenness,
It is considerably improved by increasing the discharge pressure depending on the hole diameter and hole length of the spinneret and uniformly discharging the molten polymer into each spinning hole, but other chemicals (dyeing spots, discoloration, etc.), physical (strength and elongation) Improvements in quality, yarn breakage rate, etc. were not sufficient.

Therefore, various proposals have heretofore been made to uniformly introduce the molten polymer introduced into the spinneret pack into the spinneret for the purpose of preventing the molten polymer from staying inside.

In Japanese Patent Laid-Open No. 56-148904, a distribution plate is arranged between a top insert (pack body) and a spinneret, and a distribution hole arranged in the distribution plate causes the molten polymer flow in the pack. Although a spinneret pack that evenly distributes the polymer is proposed, it is not quantified how to determine the hole diameter, hole length, number of holes, etc. of the distribution plate so that the flow of the molten polymer is not quantified. It was difficult.

Japanese Patent Publication No. 6-41644 discloses an introducing plate having a molten polymer introducing passage on the upper side of a spinneret, a distribution plate,
Further, a spinneret pack is proposed, in which a heat retaining heater is provided inside a donut-shaped pack body having a filter plate and a heating heater is provided outside the pack body.

However, this spinneret pack is specified only with respect to the heat retention of the pack and not with respect to the method of distributing the molten polymer. Therefore, depending on the distribution method, the molten polymer is retained and thermally deteriorated in a part of the pack, and the deteriorated molten polymer is discharged from the nozzle to cause yarn breakage and fineness unevenness, which is not preferable.

[0012]

Although various proposals have been made as described above, in all the publications, the hole diameter of the distribution plate,
How to determine the pore length, the number of pores, etc., to contribute to the improvement of chemical (dye spots, discoloration, etc.), physical (strength, elongation, thermal properties, etc.) quality, and yarn breakage rate It was not quantified and it was difficult to realize.

Therefore, the present invention relates to a multifilament, a spinning pack for an annular nozzle used for spinning staple fibers and the like, and a spinning method, and in particular,
The molten polymer reservoir of the top insert has an upper inclined surface,
A spinneret pack composed of a lower inclined surface facing the upper inclined surface, which prevents abnormal retention in the pack and prevents deterioration of the quality of the molten polymer, and the spinneret pack. It is an object of the present invention to provide a spinning method used.

[0014]

In order to achieve the above object, a spinneret pack according to the present invention comprises a top insert having a molten polymer inflow port at the center of the upper portion, an upper inclined surface communicating with the molten polymer inflow port, and the upper inclined line. A molten polymer reservoir which has a lower inclined surface facing the surface and guides the molten polymer flowing in from the molten polymer inlet in the outer peripheral direction, and a spinneret having a plurality of concentrically arranged spinning holes. A spinneret pack comprising: a top plate and at least one distribution plate having a plurality of distribution holes formed in each of concentrically arranged annular regions arranged between the spinneret; the ratio of the distribution plate includes a molten polymer discharge flow rate per unit area from the molten polymer discharge flow rate (Q _I) and the central annular region per unit area from the innermost annular region _{(Q C) (Q I /} Q C) , And the ratio (Q _O / Q _C ) of the molten polymer discharge flow rate per unit area from the outermost annular region (Q _O ) to the molten polymer discharge flow rate per unit area from the central annular region (Q _C ), Each is configured to be 1.2 to 1.6, and the molten polymer discharge flow rate per unit area from the central annular region to the innermost annular region and the outermost annular region is gradually increased. , Further, the distribution holes of the distribution plate have a flow rate of molten polymer per distribution hole,
Based on the spinning temperature and the viscosity of the molten polymer, the pore diameter and the pore length dimension are formed such that the pressure loss is in the range of 0.7 kg / cm ² or more and 50 kg / cm ² or less. By improving the stability in spinning and the subsequent yarn processing (drawing, false twisting, weaving process, etc. for filaments, drawing, crimping, spinning process, etc. for staples), there is less yarn breakage and fluff. Further, it is possible to reduce the occurrence of filamentous unevenness and improve the strength of the yarn.

[0015] The distribution holes density of the distribution plate is preferably 0.7 pieces / cm ² to 2.5 / cm ² or less to enable the distribution plate area.

The distribution hole of the distribution plate preferably has a narrowed portion.

Also, on both or one of the inlet side and the outlet side of the distribution plate, the upper and lower parts of each row group of the distribution holes arranged in an annular shape so that the molten polymer flow smoothly flows through the distribution hole. It is preferable that a groove channel having a concentric semicircular cross section or a V-shaped cross section is formed.

Further, it is preferable to provide a filtration layer on the upper and lower portions of the distribution plate or on either one of them.

Furthermore, it is preferable that the introduction surface angle α of the upper inclined surface that guides the molten polymer flow from the molten polymer inflow port of the top insert in the pack wall surface direction is 140 ° ≦ α ≦ 170 °.

The spinning method according to the present invention is characterized by spinning using the above-mentioned spinneret pack according to the present invention.

In the present specification, the term "annular region" (excluding the innermost and outermost annular regions) refers to the molten polymer discharge flow rate per unit area of the distribution plate. The circumference that connects the centers of the annularly arranged distribution holes that you are trying to obtain
A doughnut-shaped region surrounded by a circle connecting the centers of the two annularly arranged distribution holes and two circles in the middle of these circles (referred to as "inner adjacent middle circle" and "outer adjacent middle circle", respectively). It is used as a meaning.

The term "innermost annular region", which is an annular region arranged at the innermost circumference, cannot define the innermost intermediate circle of the innermost circle, and therefore the outermost intermediate circle and the innermost circle of the innermost circle. A circle whose radius is the distance obtained by subtracting the distance between the outer intermediate circle and the innermost circle from the radius of the circumference (called the innermost circle) that connects the arranged distribution holes. It is used to mean a donut-shaped region surrounded by and.

Further, the term "outermost annular region" annularly arranged at the outermost periphery is used to mean a donut-shaped region surrounded by the inner adjacent middle circle and the lower boundary of the upper inclined surface. .

Furthermore, the term "central annular region" is used to mean an annular region located between the outermost annular region and the innermost annular region. However, when there are even rows of annular regions, it means either one or both of the two annular regions in the middle.

The term "effective distribution plate area" in the present invention is used to mean the area where the upper surface of the spinneret contacts the molten polymer or the area or region corresponding thereto.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a first embodiment of a spinneret pack according to the present invention, showing an example of a cylindrical spinneret pack. The spinneret pack of FIG. 1 includes a pack case 1, a top insert 2 having a molten polymer inflow port 9 and a molten polymer reservoir 10, and a molten polymer distribution hole 11
A dispersion plate 3 for dispersing the molten polymer, a sand layer 12 for filtering the molten polymer, a filter layer 8 for holding the sand layer 12 and performing microfiltration of the molten polymer, a backup for the filter layer 8 and a straightening hole 13 It has a bridge plate 5 and a spinneret 6 having a spinning hole 15. On the lower surface of the bridge plate 5, a molten polymer reservoir recess 14 is formed.

The top insert 2 has a molten polymer inflow port 9 into which the molten polymer flows in the center, and a molten polymer reservoir 10 which guides the inflowing molten polymer from the molten polymer inflow port 9 to the outer peripheral side from the center. ing. The molten polymer reservoir 10 has an upper inclined surface 10a communicating with the molten polymer inflow port 9 and a lower inclined surface 10b facing the upper inclined surface 10a. In the illustrated example, the upper inclined surface 10a has a truncated cone shape, and the lower inclined surface 10b has a conical shape that is formed on the distribution plate 3 and faces the upper inclined surface 10a. .

The introduction surface angle α at this time is determined by the lower inclined surface 10
In cooperation with b, it is important for distributing the introduced molten polymer flow up to the outer peripheral portion (portion excluding the central portion), and the introduction surface angle α has an angle range of 140 It is desirable that the condition of α ≦ α ≦ 170 ° is satisfied. When the introduction surface angle α is 170 ° or more, the molten polymer is insufficiently distributed to the outer peripheral portion, and when it is 140 ° or less, the height of the top insert 2 is increased and the volume of the molten polymer reservoir 10 is increased, Along with this, the residence time increases, and thermal deterioration easily occurs.

The molten polymer flow guided from the central portion to the outer peripheral portion by the molten polymer reservoir 10 formed between the top insert 2 and the distribution plate 3 is distributed by the distribution plate 3 at a predetermined flow rate. To be done.

In the distribution plate 3, a plurality of distribution holes 11 are concentrically formed at predetermined intervals on the outer peripheral portion excluding the central portion (see FIG. 2A). Number and position of distribution holes 3,
The dimensions and the like are determined as follows. The straightening hole 13 of the bridge plate 5 and the spinning hole 15 of the spinneret 6 are also
It is formed concentrically so as to have the same axis as the distribution hole 11.

Regarding the area for determining the molten polymer discharge flow rate per unit area of the distribution plate 3, the "annular area" (excluding the innermost and outermost annular areas) is an annular arrangement for which the molten polymer discharge flow rate is to be obtained. Two circles in the middle of the circles connecting the centers of the distributed distribution holes and the circles connecting the centers of the two annular distribution holes inside and outside
They are called "inner neighbor middle circle" and "outer neighbor middle circle". ) Is defined by a donut-shaped region (see reference numeral X in FIG. 3).

Since the annular region arranged on the innermost circumference ("the innermost annular region") cannot define its inner adjacent intermediate circle, its outer adjacent intermediate circle and the distribution arranged annularly on the innermost periphery. By a circle (called an inner-adjacent virtual circle) whose radius is a distance obtained by subtracting a distance between the outer-neighboring middle circle and the inner-most circumference circle from a radius of a circle connecting the holes (which is called an inner-most circumferential circle). It is defined by a donut-shaped area (see symbol Y in FIG. 4) that is surrounded.

The "outermost annular region" annularly arranged on the outermost periphery is a donut-shaped region (Z in FIG. 5) which is surrounded by the inner adjacent middle circle and the lower boundary of the upper inclined surface 10a.
).

Further, the "central annular region" is defined as an annular region located between the outermost annular region and the innermost annular region.

The hole diameter, hole length and the number of holes of the distribution hole group of the distribution plate 3 are determined by the molten polymer discharge flow rate (Q _I ) per unit area from the innermost annular region and the unit per unit area from the central annular region. Ratio of molten polymer discharge flow rate (Q _C ) (Q _I /
Q _C ), and the ratio (Q _O / Q) of the molten polymer discharge flow rate per unit area from the outermost annular region (Q _O ) and the molten polymer discharge flow rate per unit area from the central annular region (Q _C ). _C )
However, the flow rate of the molten polymer per unit area is increased from the central annular region to the innermost and outermost annular regions for each of the annular regions therebetween. It is arranged to increase gradually, preferably in a substantially linear manner.

When the (Q _I / Q _C ) and (Q _O / Q _C ) are less than 1.2 times, the molten polymer flowing to the outer peripheral portion of the molten polymer reservoir 10 becomes insufficient, and the space where the molten polymer stays It is not preferable because it can occur. On the other hand, when (Q _I / Q _C ) and (Q _O / Q _C ) exceed 1.6 times, the molten polymer discharged from the spinning holes 15 annularly arranged at the innermost and outermost circumferences of the spinneret 6. The temperature becomes high, the yarn discharged from the spinning hole 15 tends to bend toward the central annular region side, and adjacent yarns may interfere, which is not preferable.

The distribution hole pressure loss is 0.7 kg / cm.
To be substantially constant within a range of ² or more 50 kg / cm ² or less, the distribution holes 11 of the molten polymer discharge flow rate (distribution plate 3 per one dispensing hole 11 the molten polymer total discharge flow rate in all distribution holes Number The divided value), the spinning temperature, and the viscosity of the molten polymer are used to set the pore diameter and the pore length dimension. If the distribution hole pressure loss is less than 0.7 kg / cm ² , (Q _I / Q _C )
And (Q _O / Q _C ) are smaller than 1.2, so that the flow rate of the molten polymer to the outer peripheral portion is insufficient and the desired effect cannot be obtained. On the contrary, when the pressure exceeds 50 kg / cm ² , the pressure at the molten polymer inflow port 9 is reduced due to the pressure loss due to the distribution plate 3, the filter layer 7, the sand layer 12, the filter layer 8, the bridge plate 5, and the spinneret 6 therebelow. Since it is the sum, it becomes very high, and the production time from the start of spinning is shortened, which is not preferable.

The distribution hole pressure loss (ΔP) can be calculated by the following calculation example. The distribution hole 11 is a throttle distribution hole 1.
7 (see FIG. 8C), the throttle distribution hole 17
And ΔP of the distribution holes 11 are individually calculated, and the added value is defined as ΔP specified in the present invention. By the way, in the case of a distribution hole without a narrowed portion (see FIG. 2B, distribution hole 11 in FIG. 8B), it is only necessary to calculate ΔP of the distribution hole 11. This ΔP is calculated. ΔP = (8 · η · Q · L) / (π · d ⁴ ), where η: melt viscosity Q: discharge flow rate L: distribution hole length d: distribution hole radius.

The melt viscosity η is calculated by the following equation from the shearing rate γ from the spinning polymer discharge flow rate Q, the distribution hole radius d, etc., and the shearing rate and the melt viscosity at the spinning temperature of the melted polymer used are measured beforehand. The viscosity corresponding to η calculated from the data may be obtained.

Γ = (4 · Q) / (π · d ³ ) ... This calculation formula can also be applied to the spinning hole 15 of the spinneret 6.

The molten polymer flow distributed by the distribution plate 3 is filtered by the filter layer 7 and the sand layer 12 for pressing the sand layer 12 provided at the lower part. In addition, foreign matter that has not been filtered by the sand layer 12 is also included in the sand layer 1.
It is removed by the filter layer 8 provided at the lower part of 2 for holding the sand and performing microfiltration of the molten polymer.
The filter layer 8 acts in a direction to evenly distribute the molten polymer in the upper distribution plate 3, but its degree is small. The next bridge plate 5 has a hole diameter, a hole length, and a hole number of the straightening holes 13 so as not to impair the distribution of the molten polymer flow passing through the upper filter layer 8 and the upper pack structure (distribution plate). 3, filter layer 7, sand layer 1
2. It must have mechanical properties sufficient to support the filter layer 8).

The molten polymer flow passing through the straightening holes 13 of the bridge plate 5 passes through the molten polymer reservoir recesses 14 in the upper portion of the spinneret 6, and the spinning holes 15 are arranged almost uniformly within the effective distribution plate area of the spinneret 6. Is discharged and becomes a spun yarn. The effective distribution plate area is defined by the molten polymer reservoir recess 14.

The spinning hole 15 of the spinneret 6 has a pressure loss (Δ
P) is calculated from the discharge flow rate per hole, and ΔP is 15
Normally designed to be ~ 80 kg / cm ² . As a result, the molten polymer flowing from the molten polymer reservoir recess 14 becomes larger from the central annular region toward the innermost and outermost annular regions, but the discharge flow rate from each spinning hole is changed by ΔP of the spinning hole 15. As the viscosity of the melted polymer is made uniform as well as the melted polymer, the spun yarn does not break, and the filament with uniform quality and unevenness in chemical and physical properties is stable for a long period of time. Can be produced.

In particular, it is a great feature that the main production can be started after a few minutes from the start of spinning. The reason for this is that the molten polymer flowing in the pack flows more in the vicinity of the wall surface of the pack by the distribution plate 3, so that the molten polymer in the vicinity of the wall surface of the pack, which tends to stay, can be swept away.
The temperature drop of the molten polymer deprived from the wall surface of the pack can be suppressed, and the deterioration of the molten polymer can be prevented. Further, the air in the pack at the start of discharging the molten polymer and the remaining molten polymer are also melted by the effect of the distribution plate 3. Collected in the center of the polymer reservoir recess 14, and the spinning hole 15 in the center
This is because they are discharged all at once.

In the spinneret pack shown in FIG. 1, the distribution plate 3
The position of is located under the top insert 2,
The distribution plate 3 is not particularly limited to this place, and the distribution plate 3 may be arranged directly above the spinneret 6 and the bridge plate 5 may be provided with the function of the distribution plate 3 to replace the distribution plate 3. FIG. 6 shows an example in which the distribution plate 3 is arranged directly above the spinneret 6. In the example of FIG. 6, the lower inclined surface 10b of the molten polymer reservoir 10 is formed on the upper surface of the bridge plate 5.

The shape of the distribution plate 3 is not limited to that shown in the first embodiment, but may be various shapes such as a truncated cone shape. As another example, the present invention will be described below. A second embodiment of such a spinneret pack will be described with reference to FIGS. 7 and 8.

FIG. 7 is a longitudinal sectional view of the spinneret pack according to the second embodiment. 8 (a) and 8 (b) are a plan view and a vertical cross-sectional view showing a distribution plate incorporated in the spinneret pack of FIG. 7, and FIG. 8 (c) is a vertical section showing a modification of the distribution plate. It is a side view. In the spinneret pack according to the second embodiment, as shown in FIG. 7, the upper surface of the distribution hole of the distribution plate 3 has a conical shape including the surface on which the distribution hole 11 is formed.
Furthermore, the point that the concentric V-groove portions 16 (see FIG. 8A) are provided on the upper and lower surfaces of the annularly arranged distribution hole array group is the first aspect.
Unlike the first embodiment, the other points are the same as those of the first embodiment, and thus detailed description thereof will be omitted. Also in the spinneret pack according to the second embodiment having the distribution plate 3 having such a shape, the residence time of the molten polymer can be shortened and deterioration of the molten polymer can be prevented, like the spinneret pack of the first embodiment. In addition, the flow rate of the molten polymer designed in the distribution holes can be flowed more accurately, the stability in spinning is improved, and the number of yarn breakages and fluffs in the subsequent yarn processing is small,
The occurrence of filamentous unevenness can be further reduced.

In the first and second embodiments described above,
Although only the cylindrical spinneret pack has been described, the spinneret pack according to the present invention is not limited to the cylindrical shape, and may have a rectangular parallelepiped shape or a cubic shape. In this case, the top insert 1 and the distribution plate 3 can have various shapes as shown in the perspective views of FIGS.

[0050]

EXAMPLES The spinneret packs of Examples 1 and 2 of the present invention and Comparative Examples 1 and 2 for comparison with the present invention were manufactured according to the conditions shown in Table 1 below, and comparative experiments were conducted. The basic structure of each spinneret pack is the same as that of the spinneret pack shown in FIG. 1, but the number of distribution holes and the hole diameter are different.

[0051]

【table 1】

In Table 1, "PCD" is "pitch circle d
iameter (pitch center circle diameter) "and means the diameter of the circle connecting the centers of the distribution holes formed in the annular region of interest.

The distribution holes of the distribution plate are concentrically arranged at the same pitch in the effective distribution plate area in any of the examples and comparative examples.

In each spinneret pack, the effective distribution plate area of the distribution plate is 200 mm in diameter and 120 mm in diameter.
Is a doughnut-shaped area surrounded by a circle, and the distribution holes circumferentially arranged in the area have no narrowed portion and the hole length is 15 mm. Using such a spinneret pack, the intrinsic viscosity η Is 0.63 and contains 1162 denier of polyethylene terephthalate containing 0.3% by weight of titanium oxide.
A filament of 0 filament (1162D / 900F) was spun at a spinning temperature of 290 ° C. with 0.8% of a normal filament oil agent attached, spun at a spinning speed of 3100 (m / min), and wound. Further, by the subsequent stretching step, a stretching speed of 1000
The fiber was treated with a (m / min) drawing machine, and the spinning breakage rate was calculated from the number of breaks during spinning and drawing.

The respective evaluation items are as follows.

Spinning breakage rate: Spinning breakage rate (times / ton) = Number of breakages generated during spinning / Production amount (ton) Stretching breakage rate: Stretching breakage rate (%) = (breakage during drawing Table 2 shows the number of yarn-generated yarns / the number of yarn-breakage yarns) / the amount of production (ton). The staining spots are evaluated on a scale of 5 and the best is 5 (no stains are seen) and the lowest is 1 (there are many stain spots).

[0057]

[Table 2]

As is clear from Table 2, in all of the examples, the yarn breakage rate is extremely low and the stability and quality stability in the spinning and drawing process are excellent as compared with the comparative example. These causes are because the chemical and physical properties of all the single yarns of the spun yarns obtained from the respective spinning holes are made uniform, and in the example, when the breaking strength and elongation of all the drawn yarns are measured, The drawn yarn of this example is large in both strength and elongation,
Due to the fact that there is very little variation among them, the above-mentioned excellent properties are exhibited.

Although not shown in Tables 1 and 2, the time during which the molten polymer was discharged from each Example and Comparative Example and the main winding could be started (this time was about 2800 m of the spun yarn with a high-speed waist air gun). It takes about 5 to 1 in Examples 1 and 2 when it is taken out at a rate of 5 minutes per minute, and is determined from the time at which yarn breakage and discoloration due to heat-deteriorated molten polymer by observing this situation disappear.
You can move to the main roll in 0 minutes. Comparative Example 1 was 60 minutes or longer, and Comparative Example 2 was slightly faster, about 45 minutes. In these comparative examples, a great number of yarn breaks occur at the outermost peripheral portion of the spinneret, and the periodicity of the yarn breaks is observed. This is because the heat-degraded decomposed molten polymer in the outermost peripheral part has a low viscosity and is easily discharged from the spinning hole on the outer peripheral side, and when the decomposed molten polymer is almost discharged, the next new molten polymer is in the outermost peripheral part. It seems that periodicity was observed due to re-retention and a certain amount of time was required to decompose the retained molten polymer.

[0060]

As is apparent from the above description, the spinneret pack according to the present invention has improved stability in spinning and less yarn breakage, fluff, etc. in the subsequent yarn processing, and reduces the occurrence of yarn unevenness. Can be made.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a spinneret pack according to the present invention.

2 (a) is a plan view of the distribution plate of FIG. 1, FIG.
2B is a vertical cross-sectional view taken along the line AA of FIG.

FIG. 3 is a plan view corresponding to FIG. 2A showing a (center) annular region.

FIG. 4 is a plan view corresponding to FIG. 2A showing an outermost annular region.

FIG. 5 is a plan view corresponding to FIG. 2A showing an innermost annular region.

6 is a longitudinal sectional view showing a modified example of the spinneret pack of FIG.

FIG. 7 is a vertical sectional view showing a second embodiment of the spinneret pack according to the present invention.

8 (a) is a plan view of the distribution plate of FIG. 7, and FIG. 8 (b) is a vertical sectional view taken along the line BB of FIG. 8 (a).
FIG. 9C is a vertical cross-sectional view showing a distribution plate in which the distribution holes of FIG.

FIG. 9 is a perspective view showing a top insert and a distribution plate of a spinneret pack having a rectangular parallelepiped shape according to the present invention.

FIG. 10 is a perspective view showing a top insert and a distribution plate of another aspect of the spinneret pack having a rectangular parallelepiped shape according to the present invention.

FIG. 11 is a longitudinal sectional view showing a conventional spinneret pack.

[Explanation of symbols]

1 pack case 2 Top insert 3 distribution plates 4 sand cases 5 bridge plate 6 Spinneret 7 filter layers 8 filter layers 9 Molten polymer inlet 10 Molten polymer reservoir 10a Upper slope 10b Lower slope 11 distribution holes 12 Sand layer 13 straightening hole 14 Recess for molten polymer reservoir 15 Spinning holes 16 groove 17 Aperture distribution hole

Claims (7)

[Claims] 1. A top insert having a molten polymer inlet at the center of the upper portion, an upper inclined surface communicating with the molten polymer inlet, and a lower inclined surface facing the upper inclined surface, and from the molten polymer inlet. A molten polymer reservoir for guiding the inflowing molten polymer to the outer peripheral direction, a spinneret having a plurality of concentrically arranged spinning holes, and a concentric array arranged between the top insert and the spinneret. A spinneret pack having at least one distribution plate having a plurality of distribution holes perforated in each of the annular regions, wherein the distribution plate is a molten polymer discharge flow rate per unit area from the innermost annular region. (Q _I ) to the molten polymer discharge flow rate (Q _C ) per unit area from the central annular region (Q _I /
Q _C ), and the ratio (Q _O / Q) of the molten polymer discharge flow rate per unit area from the outermost annular region (Q _O ) and the molten polymer discharge flow rate per unit area from the central annular region (Q _C ). _C )
Are each 1.2 to 1.6, and the molten polymer discharge flow rate per unit area from the central annular region to the innermost annular region and the outermost annular region is gradually increased. is configured, furthermore, distribution holes of the distributor plate, 1 molten polymer flow rate per distributing hole, based on the spinning temperature, and molten polymer viscosity, the pressure loss is 0.7 kg / cm ² or more 50 kg / cm ²
A spinneret pack characterized in that the hole diameter and the hole length dimension are formed so as to fall within the following ranges. 2. The spinneret according to claim 1, wherein the distribution hole density of the distribution plate is 0.7 pieces / cm ² or more and 2.5 pieces / cm ² or less within the effective distribution plate area. pack. 3. The spinneret pack according to claim 1, wherein the distribution hole of the distribution plate has a narrowed portion. 4. Both the inlet side and the outlet side of the distribution plate,
Or, on the other hand, a concentric grooved semicircular or V-shaped groove channel is formed in the upper and lower portions of each row of the distribution holes arranged in an annular shape so that the molten polymer flow smoothly flows through the distribution holes. The spinneret pack according to any one of claims 1 to 3, wherein 5. The spinneret pack according to claim 1, wherein a filtration layer is provided on the upper and lower portions of the distribution plate or on one of them. 6. The introduction surface angle α of the upper inclined surface for guiding the molten polymer flow from the molten polymer inflow port of the top insert toward the pack wall surface is 140 ° ≦ α ≦ 170 °. Spinneret pack. 7. A spinning method, which comprises spinning using the spinneret pack according to claim 1.