JP2003342827A - Melt-spinning spinneret pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a melt spinning spinneret pack which can reduce process troubles such as fiber breakages caused by the abnormal stay and deterioration of a polymer and further reduce the development of fiber quality irregularity. <P>SOLUTION: This melt-spinning spinneret pack (1) comprises at least a polymer inflow member (3) having a polymer inflow hole formed therein and a flow-spreading passage for spreading the polymer flowed in the lower portion of the inflow hole, a metal net filter (4) for directly filtering the polymer spread in the lower portion of the polymer inflow member (3), a distribution member (3) which supports the metal net filter (4) just thereon and in which a peripheral passage (501) for distributing the polymer passed through the metal net filter (4) to the peripheral side and a joining passage (502) for joining the polymer distributed into the peripheral passage (501) are formed, and an engaging support member (6) which supports a distribution member (5) in an engaged state and in which a polymer supply hole for supplying the polymer joined and supplied from the distribution member (5) to a just upper filter (7) disposed just on a spinneret (8) is formed. <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 melt-spinning spinneret pack for melt-spinning a thermoplastic polymer such as polyester, polyamide and polyolefin.

[0002]

2. Description of the Related Art Generally, in melt spinning of thermoplastic synthetic fibers such as polyester, polyamide and polyolefin,
BACKGROUND ART A spinneret pack (hereinafter sometimes simply referred to as "pack") for removing foreign matters in a spin melt and favorably ejecting the spin melt from a spinneret to form fibers is used.

The structure of such a pack is, for example, as shown in FIG.
1c is generally used which includes a spinneret 12, a polymer distribution plate 13, filters 14a to 14c, and a filter medium 15 made of metal sand. In FIG. 4, the pack body 11c also serves as a polymer introducing member, and is fastened by means of a fastening means (for example, a hexagon socket head bolt) of the pack provided in a portion indicated by a chain line.

In such a pack 10, since the filter layer 15 made of metal sand or the like is provided,
There is a problem that the residence amount of the polymer in this portion increases and the residence time of the polymer increases accordingly.

Further, when a thermoplastic polymer such as polyester or polyamide stays in the pack for a long time in a heated state, the thermoplastic polymer is thermally deteriorated to cause yarn breakage or quality unevenness. Further, since such a polymer is a highly viscous material, the flow velocity on the outside of the flow channel tends to decrease due to the wall surface resistance of the flow channel and the like. Moreover, in such a pack, since the outer peripheral surface of the pack body 11 is surrounded by a heat retaining / heating device (not shown) except for the polymer discharge surface of the mouthpiece 12, there is a gap between the center part and the peripheral part of the pack. Temperature difference occurs in pack 1
The polymer flowing in the inner flow channel outside 0 receives more heat than the polymer flowing in the inner flow channel inside.

In such a state, when the factors of the thermal history difference and the residence time difference generated in the internal flow passages at the central portion and the peripheral portion in the pack 10 are superposed, they are located on the outer peripheral side of the pack 10. Polymer deterioration is likely to occur in the low flow velocity portion of the internal flow path. Therefore, in order to avoid such a situation, conventionally, the polymer flowing in from the polymer introducing member 11c of the pack body 11 is uniformly heated in the pack 10 without being abnormally retained in the base 12 for a long time. However, various studies have been carried out for making the fluid flow smoothly and spinning it from the spinneret 12.

[0007] For example, as a technique for solving the above-mentioned problem, in Japanese Unexamined Patent Publication (Kokai) No. 11-810310, a plurality of grooves are provided in the distribution plate 13 below the filtration layer 15 along the flow direction of the polymer, and adjacent grooves are provided. There has been proposed a distribution plate in which a ridge line portion is formed in the mountain portion so that the contact portion composed of the mountain portion is in surface contact and the priller does not enter the surface contact portion, and the line contact is made.

However, even with such a distribution plate, it is difficult to avoid some degree of abnormal retention of polymer at the line contact portion,
Under severe conditions such as heating from below the spinneret, deterioration of the polymer occurs after a certain period of time, causing frequent yarn breakage, and therefore its effect is not sufficient.

Further, Japanese Patent Application Laid-Open No. 2000-265316 discloses a polymer distribution plate having a plurality of rectifying holes of which dimensions are defined. However, even the distribution plate having such a structure has a heat history difference in a state where the heat history difference between the upstream side thereof, particularly the center part and the peripheral part of the filtration layer 15 having a long residence time is maintained as it is. The polymer will flow into the base. Therefore, the base 1
There is a problem that unevenness is generated between the polymer discharged from the discharge holes formed on the outer peripheral side of the nozzle 2 and the polymer discharged from the discharge holes formed on the inner peripheral side.

When abnormal retention of the polymer occurs at a certain position in the pack 10 in the first place, not only the deterioration of the process condition such as yarn breakage but also the deviation of the heat receiving amount of the polymer, that is, the heat history is caused. The polymer locally deteriorates to gel or carbonize, and the yarn quality itself deteriorates.

[0011]

Therefore, in order to solve the above-mentioned various problems, the abnormal retention of the polymer in the pack is reduced as much as possible, and the pack is packed before the polymer is introduced into the die. It is necessary to have a structure that minimizes the thermal history difference generated between the central portion and the peripheral portion and shortens the residence time as much as possible.

[0012] Therefore, the present invention provides a spinneret pack for melt spinning, which can reduce deterioration of the process condition such as yarn breakage due to abnormal retention of polymer and deterioration of polymer, and generation of unevenness of yarn quality. The purpose is to do.

[0013]

In order to solve the above-mentioned problems, the present invention provides a "melting method including a spinneret having discharge holes for discharging a polymer in a fibrous state. A spinneret pack, wherein the spinneret pack is provided with an inflow hole through which a polymer flows, and a polymer inflow member having a flow-expanding flow path for expanding the inflowing polymer in a lower portion of the inflow hole. A wire mesh filter for directly filtering the polymer expanded in the expanded state at the lower part of the polymer inflow member, and supporting the wire mesh filter directly above it,
A distribution member formed with an outer peripheral flow passage that distributes the polymer that has passed through the wire mesh filter to the outer peripheral side thereof, and a re-merging flow passage that causes the polymer distributed to the outer peripheral flow passage to re-merge while flowing to the downstream side, And a member for engaging and supporting the distribution member, and further having a polymer supply hole for supplying the polymer re-merged from the distribution member and supplied to the filter directly above the spinneret provided directly above the spinneret. A melt spinning spinneret pack comprising at least a composite support member is provided.

At this time, in the spinneret pack for melt spinning of the present invention, the gap between the polymer spreading start position at the lower end of the inflow hole of the polymer inflow member and the filtration surface of the wire mesh filter is 0.1 mm or more, and 5. It is preferably 0 mm or less, and a flow path interval forming member for always maintaining a constant flow path interval between the outer peripheral flow path and the re-merging flow path is used for the flow of the outer peripheral flow path and the re-merging flow path. It is preferable to provide the passage connecting portion, and further, it is preferable that the flow passage distance between the outer peripheral flow passage and the re-merge flow passage is 0.1 mm or more and 2 mm or less.

Further, the spinneret pack for melt spinning of the present invention comprises:
The inner diameter of the polymer supply hole is preferably 5 mm or less, and it is further preferable to provide a static mixing element in the polymer supply hole in order to achieve the object of the present invention.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a spinneret pack for melt spinning of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic explanatory view exemplifying to explain the pack of the present invention, and shows a schematic front cross section. In this figure, reference numeral 1 indicates a spinneret pack for melt spinning, and the pack 1 comprises a pack case 2 and various pack members incorporated in the pack case 2.

Here, various pack members incorporated in the pack case 2 include a polymer inflow member 3, a wire mesh filter 4 having a seal member on the outer peripheral edge thereof, and a distributor in order in the direction of introduction of the polymer shown by the arrow in FIG. It comprises at least a member 5, an engagement support member 6 having a polymer supply hole formed therein, a filter 7 directly above the mouthpiece, a mouthpiece 8 and a static kneading element 9.

At this time, in this example, it is preferable that the polymer inflow member 3 is divided into upper and lower members so that the polymer inflow member 3 can be divided according to its function. That is,
The upper dividing member is a fastening member 3a for fastening with a constant torque so that the polymer does not leak from the pack 1 when various pack members are assembled in the pack case 2, and the lower dividing member is the wire mesh filter. In order to make the filtration area of 4 wide, it is preferable to use the spreading member 3b for spreading the flow of the polymer. Reference numeral 3c is a seal member for preventing the polymer from leaking from a connecting portion connecting the fastening member 3a and the flow spreading member 3b.

At this time, it is necessary that the polymer inflow member 3 is not provided with the filtration layer 15 as in the conventional pack 10 illustrated in FIG. That is, if the filtration layer 15 as found in the conventional pack 10 is provided, the polymer stays in the filtration layer 15 for a long time, and the polymer deteriorates due to the heat history. Therefore, in the polymer inflow member 3 of the present invention, the polymer inflow hole is provided with a diverging portion continuing from the polymer inflow hole, and when the diverging is completed, the polymer is immediately passed through the wire mesh filter 4 to remove foreign matters in the polymer.

However, in order to remove the foreign matter by passing the polymer through the wire mesh filter 4, it is possible to prevent the foreign matter trapped in the wire mesh filter 4 from being clogged, and to prevent the filtration pressure from increasing, and to prevent the permeation of the polymer per unit flow rate. In order to increase the filtration area and prevent the filtration pressure from rising, it is necessary to spread the polymer as in this example before entering the wire mesh filter 4. At this time, the distance A between the polymer spreading start position at the lower end of the inflow hole of the polymer inflow member 3 and the filtration surface of the wire mesh filter 4 (indicated by reference numeral A in FIG. 1) is The smaller the size, the better, but practically, it is preferably 5.0 mm or less in order to prevent thermal deterioration of the polymer even when the residence amount and residence time of the polymer are taken into consideration. However, since such a condition also depends on the sensitivity of the polymer to heat, it is preferable to appropriately determine the value of the interval A by an experiment according to the actual use condition. Also, this interval A is 5.
When it is larger than 0 mm, the polymer flow velocity is remarkably lowered particularly in the center of the filter, and it is difficult to replace the polymer, which causes abnormal retention, which is not preferable.

However, it is not preferable to make the interval A too small, because it hinders the diffusion of the polymer to the outer peripheral portion and the filtration area of the wire mesh filter cannot be effectively used, and it is not less than 0.1 mm. Preferably.

A seal member made of a material such as aluminum is formed on the outer peripheral edge of the wire mesh filter 4, and the pack case 2 and the fastening member 3a are screwed and fastened to each other at their threaded portions. At this time, the seal member is sandwiched between the outer lower end of the flow expanding member 3b and the engagement support member 6, thereby preventing the polymer from leaking to the outside of the pack 1.

Next, regarding the engaging support member 6 that supports the wire mesh filter 4 immediately above it, a static mixing element (static mixer) 9 is provided in the polymer supply hole for supplying the polymer to the die 8. Is a preferred embodiment. Because by adopting such an aspect,
The streamlines of the high-viscosity molten polymer in which the streamlines of the polymers flowing on the wall surface side and the center side of the polymer channel do not interchange with each other can be interchanged. Further, by the static mixing element 9, the polymers are uniformly mixed, so that the polymers having different thermal histories are uniformly mixed, so that the polymers can be homogenized.

Here, as the static mixing element 9, a known Kenix type or Sulzer type static mixing element is usually used, and the larger the number of divisions of the mixing element, the more the polymer mixing effect is improved. Although preferable, as the number of divisions increases, the length of the static mixing element also increases correspondingly,
There is a problem in that the residence length of the polymer (long residence time) and the overall height of the pack 1 also become long. However, in the pack 1 of the present invention, the conventional pack 10 as illustrated in FIG.
Unlike the conventional pack 10, unlike the conventional pack 10, the static mixing element 9 can be installed in a long length because the filter layer 15 is not provided, and the number of divisions can be increased. Can be designed to be the same. As for the inner diameter (indicated by reference numeral D in FIG. 1) of the polymer supply hole in which such a static mixing element 9 is provided, if the value of this D is made too large, the retention amount of the polymer increases, so It is preferably 5.0 mm or less, and further preferably smaller when the static mixing element 9 is not provided. For example, 2.0 mm or less depending on the usage conditions of the pack in melt spinning. You can also do it. However, it is not preferable to make the inner diameter D too small, because the production of the polymer supply hole becomes difficult and the production cost increases, and the pack pressure on the upstream side increases due to the flow path resistance. The thickness is preferably 0.2 mm or more because it causes undesirable problems such as polymer leakage from the pack.

In the pack 1 constructed as described above, in the present invention, the distribution member 5 also plays an extremely important role together with the polymer inflow member 3, so for the embodiment of this distribution member, refer to FIG. However, a detailed description will be given below. 3 shows the polymer inflow member 3, the wire mesh filter 4, the distribution member 5, and
FIG. 4 is a schematic explanatory view (normal cross-sectional view) partially enlarged in order to explain a flow state of a polymer flowing through the engagement supporting member 6. In addition, in FIG. 3, regarding the wire mesh filter 4 whose structure is difficult to understand in FIG.
It has been clarified again that the wire mesh filter is composed of a wire mesh portion indicated by reference numeral 4a and a rim portion indicated by reference numeral 4b.

2A and 2B are explanatory views for explaining an embodiment of the distribution member 3. FIG. 2A is a plan view and FIG. 2B is a side sectional view. In addition, in this FIG.
Reference numeral 5a is a distribution member main body, and reference numeral 5b is a flow path interval forming member for maintaining a constant flow path interval between the engaging support member 6 and the polymer.

By providing the flow path interval forming member 5b, the outer peripheral flow path indicated by the reference numeral 501 is provided between the main body 5a and the engaging support member 6 which supports the main body 5a and supports it. It is possible to maintain a constant flow path interval of the re-merging flow path indicated by reference numeral 502. In addition, the flow path interval forming member 5b includes the outer peripheral flow path 501 and the re-merging flow path 502.
1 is provided in the flow path connecting part of FIG.
It is possible to simultaneously set the intervals of the outer peripheral flow channel 501 and the interval of the re-merging flow channel 502, which are respectively indicated by C and C, to predetermined values.

Here, since the requirement that the flow path interval forming member 5b should have is to secure the intervals B and C, the flow path interval forming member 5b is the engagement support member 6.
It is preferable that the portion that comes into contact with is as small as possible. if,
If possible in design, it is preferable to eliminate such a contact portion. The reason for this is that the polymer may also enter the slight gap generated in this contact portion and stay for a long time. In addition, the flow path interval forming member 5b
3 is attached to the main body 5a portion of the distribution member 5 in the example of FIG. 3, but may be attached to the engagement support member.

Regarding the interval B of the outer peripheral flow channel 501 and the interval C of the re-merging flow channel 502 formed as described above, this interval minimizes the amount of polymer retention in this portion. In order to prevent thermal deterioration, it is preferable that it is as small as possible. However, since it depends on the melt spinning conditions, it is preferable to appropriately determine it by experiments as in the case of the interval A, but it is practically 2.0 mm. If it is below, it does not cause a big problem.

However, if the intervals B and C are made too small, the manufacturing dimensional accuracy of the pack is required.
It is not preferable, and since the pack pressure on the upstream side increases due to the flow path resistance, which causes an unfavorable problem such as polymer leakage from the pack, it is preferably 0.1 mm or more. However, if the interval C of the re-merging flow path formed between the engagement support member 6 and the engagement support member 6 is larger than 2.0 mm, the polymer substitution is impaired particularly in the outer peripheral portion where the polymer flow velocity tends to be low, and abnormal retention occurs. It is not preferable because it easily occurs.

In the pack 1 of the present invention described above, FIG.
The polymer flows in from the direction indicated by the arrow and sequentially passes through the various pack members having the above-described configuration incorporated in the pack case 2, and then the filter 7 directly above the cap 7
Through a discharge hole formed in the spinneret 8 to be fibrous and melt-spun. At that time, it is needless to say that the pack 1 of the present invention was superior to the conventional one in terms of its spinning condition and quality of the obtained fiber. Therefore, regarding this point, the results of experiments using the pack of the present invention will be described below in detail with reference to Examples.

[0033]

EXAMPLES Using the spinneret pack for melt spinning of the present invention, polyethylene terephthalate having a spinning temperature of 295 ° C. and an intrinsic viscosity (IV) of 1.0 was melt-spun at a spinning speed of 800 m / min, and further heated on a heating roll. After preheating at 90 ℃,
Stretching was performed at a stretch ratio of 4.0 times.

At this time, as the pack, a pack having substantially the same structure as that illustrated in FIG. 1 was used. At this time,
The static mixing element 9 is not used, a filter composed of a metallic non-woven fabric is used as the wire mesh filter 4, and
The mouthpiece 8 used was one in which five polymer discharge holes were formed in the inner circumference and ten in the outer circumference, and a total of 15 holes were formed in a double concentric shape.

At this time, in order to visualize the abnormal residence of the polymer in the pack 1, a small amount of chips containing a pigment are mixed with the above-mentioned raw material polymer, the mixture is supplied to a known melt-kneading extruder, and a fixed amount is measured by a metering pump. According to a known melt-spinning method of continuously feeding the molten polymer of Example 1 to a melt-spinning apparatus equipped with the pack of the present invention. At this time, the polymer was supplied to the pack for a certain period of time and, after sufficient discharge, the pack was disassembled, and the presence or absence of a retained part was determined as the abnormally retained part of the polymer where the coloring remaining from the pigment chips remained. . Further, as an evaluation item of the spinning tone, the frequency of single fiber breakage during melt spinning was observed, and this was evaluated by the number of stretched yarn breakages within 5 days after the start of spinning. Furthermore,
Unevenness is taken up as an item for evaluating the quality of the yarn. Regarding this, single filaments spun from polymer discharge holes formed on the inner peripheral side and the outer peripheral side of the spinneret (hereinafter referred to as "single yarn"). (Referred to below) was collected, and the yarn unevenness was determined by the size of the IV difference between the single yarns. The results thus obtained are shown in Table 1 together with the dimensions of the flow path parameters A, B, C, and D of the pack shown in FIG.

[Example 1, Comparative Example 1-3] The abnormal retention portion in Comparative Example 1 shown in Table 1 was observed near the outer periphery of the polymer inflow member 3b and in the central portion of the wire mesh filter 4. Further, the abnormal retention portion of Comparative Example 2 was minutely generated in the lower outer peripheral portion of the engagement support member 6. Further, in Comparative Example 3, in the discharge test with the colored polymer, a difference in shade between the polymer coming out from the outer peripheral side discharge hole and the polymer coming out from the inner peripheral side discharge hole was observed.

[0037]

[Table 1]

[0038]

INDUSTRIAL APPLICABILITY As described above in detail, in the pack of the present invention, the amount of polymer retained in the pack is remarkably reduced, and the average residence time thereof is extremely shortened, as compared with the conventional pack. It is possible to suppress the deterioration due to the heat history received while staying in the pack. Therefore, in the spinning process including the melt-spinning process, the process tone can be favorably maintained, and the obtained yarn can be homogeneous and excellent in quality without variation, which is a particularly remarkable effect. Play.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view illustrated to explain a pack of the present invention, showing a schematic front cross section.

FIG. 2 shows an embodiment of a distribution member according to the present invention,
(A) A schematic plan view and (b) a schematic side sectional view.

FIG. 3 is a partial enlarged view (front sectional view) for explaining a flow state of a polymer flowing through a main part of the pack of the present invention.

FIG. 4 is a schematic explanatory view exemplifying for explaining a conventional pack, showing a schematic front cross section.

[Explanation of symbols]

1 pack 2 pack case 3 polymer inflow member 4 wire mesh filter 5 distribution member 6 engagement support member 7 filter directly above the spinneret 8 spinneret 9 static mixing element 501 outer peripheral flow channel 502 re-merging flow channels A, B, C, D Flow path parameters of the flow path

Claims (6)

[Claims] 1. A melt-spinning spinneret pack comprising a spinneret having discharge holes for discharging a polymer in a fibrous state, wherein the spinneret pack has an inflow hole through which the polymer flows. A polymer inflow member provided with a flow-expanding channel for expanding the polymer that has flowed in at the lower part of the inflow hole, and a wire mesh filter for directly filtering the polymer expanded at the lower part of the polymer inflow member in the expanded state Supporting the wire mesh filter immediately above it, and further re-joining while flowing the polymer distributed in the outer peripheral flow path to the outer peripheral flow path that distributes the polymer that has passed through the wire mesh filter to the outer peripheral side while flowing downstream. A distribution member having a rejoining flow path formed therein, and a support member engaged and supported by the distribution member, and the polymer supplied by rejoining from the distribution member is directly provided on the spinneret. At least comprising melt spinning spinneret pack from the engaging support member polymer feed hole is bored supplied to the filter. 2. The melt spinning according to claim 1, wherein a distance between a polymer spreading start position at a lower end of the inflow hole of the polymer inflow member and a filtration surface of the wire mesh filter is 0.1 mm or more and 5.0 mm or less. Base pack. 3. A flow channel interval forming member for always maintaining a constant flow channel interval between the outer peripheral flow channel and the re-merging flow channel is provided in a flow channel connecting portion between the outer peripheral flow channel and the re-merging flow channel. Claim 1
Or the spinneret pack for melt spinning according to 2. 4. The flow path interval between the outer peripheral flow path and the re-merging flow path is 0.1 mm or more and 2.0 mm or less.
A spinneret pack for melt spinning according to any one of 3 to 3. 5. The polymer supply hole has an inner diameter of 0.2 mm.
As described above, the melt-spinning die pack according to any one of claims 1 to 4, having a thickness of 5.0 mm or less. 6. The spinneret pack for melt spinning according to claim 1, wherein a static mixing element is provided in the polymer supply hole.