JP2005273039A - Method and apparatus for producing extra fine synthetic fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for producing an extra fine fiber, with which a multifilament synthetic fiber having a fine single fiber fineness is produced without lowering productivity and deteriorating qualities by installing a spinneret having a given ejection hole specification and a specified ejection hole arrangement in a spinning machine with taking the direction of cooling air into consideration. <P>SOLUTION: In the method for producing an extra fine fiber having ≤0.9 dtex single fiber fineness by a melt spinning method, the spinneret (A) having ≥70 ejection holes, (B) forming ejection hole groups each composed of ≥3 ejection holes having 0.8-3.5 mm gap between the ejection holes and (C) having 5-27 mm gap H between the ejection hole groups is used and a blowing-out apparatus for cooling air below the spinneret is (a) a cooler of uniflow type, has (b) a distance L between the top part of blowing out of cooling air and the spinneret of 20-80mm and has (c) the ejection hole arrangement in the ejection hole groups laid not to be in the same direction as the air direction of the cooling air. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing an ultrafine synthetic fiber, and more particularly to a method and an apparatus for producing an ultrafine synthetic fiber using a melt spinning apparatus having a uniflow type cooling device which is the most common melt spinning apparatus.

  Synthetic fibers produced by melt spinning, such as polyester and polyamide, are used in a wide range of fields because of their characteristics (easy care, chemical resistance, etc.). Under such circumstances, in the field of clothing, improvements such as diversified cross-section (such as glossiness) and polymer modification (coloring property after dyeing, antistatic property, etc.) have been added due to diversification of needs. One of these improvements is the fine single yarn fineness and the multifilamentization, which can give a soft touch to the resulting fabric.

  In order to make fine single yarn fine and multifilament, the technical point is how to cool uniformly in the spinning process. In general, the spinning equipment is a system (uniflow type) that cools the polymer discharged from the circular spinneret from one direction, but the discharge filament closer to the cooling air blowing surface is cooled, but the far side Since the cooling air does not pass through the discharge filament located at, the forced cooling is not performed at all.

  In order to solve this problem, a method of installing an annular cooling device for uniform cooling has been proposed (see Patent Documents 1 to 3). Furthermore, there has been proposed an attempt to obtain an ultrafine yarn by optimizing the nozzle discharge hole arrangement corresponding to the annular cooling device (see Patent Document 4). However, in these cases, remodeling from a general spinning facility (uniflow type) to an annular cooling device is a prerequisite, and large-scale facility remodeling is involved.

In order to avoid this problem, a method of providing discharge holes in a double square lattice shape has been proposed (see Patent Documents 5 and 6). According to these proposals, it is possible to efficiently apply the cooling air blown from one direction to the yarn cooling by further arranging the group in which the discharge holes are arranged in a square lattice pattern. However, in this method, since the mutual relationship between the spinning cooling air and the direction of the discharge hole arrangement is not taken into consideration, the objectives of finer single yarn fineness and multifilamentization have not necessarily been achieved.
JP 55-90609 A Japanese Patent Laid-Open No. 62-243824 JP-A-9-226920 JP 7-278940 A Japanese Patent Laid-Open No. 5-125609 JP-A-7-300716

  An object of the present invention is to solve such problems of the prior art, and spins a die having a specific discharge hole specification and a specific arrangement of discharge holes on the premise that no significant facility modification is performed. By installing in the spinning machine taking into consideration the direction of the cooling air, it is possible to produce fine single yarn fineness and multifilament synthetic fibers without reducing productivity and without deteriorating quality. Another object of the present invention is to provide a manufacturing method and a manufacturing apparatus for an ultrafine synthetic fiber.

In order to solve the above-described problems, the present invention employs the following configuration. That is,
(1) When producing an ultrafine synthetic fiber having a single yarn fineness of 0.9 dtex or less by a melt spinning method,
(A) having 70 or more discharge holes,
(B) A group consisting of three or more discharge holes having a discharge hole interval S of 0.8 mm to 3.5 mm,
(C) A base having an interval H between the discharge hole groups of 5 mm or more and 27 mm or less is used.
The cooling air blowing device under the base
(A) A uniflow type cooling device,
(B) The distance L between the uppermost part of the cooling air blowing and the base is 20 mm or more and 80 mm or less,
(C) A method for producing an ultrafine synthetic fiber, characterized in that the discharge hole array in the discharge hole group of the die is installed so as not to be aligned in the same direction as the cooling air for cooling the spun yarn.

  (2) The method for producing an ultrafine synthetic fiber according to (1), wherein all the discharge holes each use a base having an introduction hole independently.

(3) In an apparatus for producing an ultrafine synthetic fiber having a single yarn fineness of 0.9 dtex or less by a melt spinning apparatus,
(A) having 70 or more discharge holes,
(B) A group consisting of three or more discharge holes having a discharge hole interval S of 0.8 mm to 3.5 mm,
(C) A base having an interval H between the discharge hole groups of 5 mm or more and 27 mm or less is used.
The cooling air blowing device under the base
(A) A uniflow type cooling device,
(B) The distance L between the uppermost part of the cooling air blowing and the base is 20 mm or more and 80 mm or less,
(C) An apparatus for producing ultrafine synthetic fiber, wherein the discharge hole array in the discharge hole group of the die is installed so as not to be aligned in the same direction as the cooling air for cooling the spun yarn.

  By adopting the production method of the present invention, it is possible to produce high-quality ultrafine synthetic fibers with high productivity even when general spinning equipment is used. This is a level that can be achieved by making major modifications to the spinning equipment in the prior art, and the manufacturing method of the present invention has a revolutionary effect in terms of cost and operation of the production equipment on the premise of low-volume, multi-product production. .

The production method of the present invention can be applied to all synthetic fibers obtained by a melt spinning method in which a molten polymer is cooled and solidified in the air, such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polylactic acid. It can be preferably applied to polyester, polyamides such as nylon 6 and nylon 66, and the single yarn fineness of 0.9 dtex (for the differentiation of polyethylene terephthalate, which is a so-called general-purpose synthetic fiber, and polyamides such as nylon 6 and nylon 66, etc. (Decitex) It can be suitably used for producing the following multifilament yarns. However, these polymers may contain titanium oxide or the like as a matting material, or may contain a copolymer. As the single yarn fineness decreases, the solidification point of the discharged polymer approaches the base surface, and the yarn uniformity tends to deteriorate. For this reason, a case where a yarn of satisfactory quality cannot be obtained depending on the use is assumed, and in order to avoid such a problem, it is preferable to apply the present technology to an ultrafine yarn having a single yarn fineness of 0.2 dtex or more.

  On the other hand, the quality advantage when the synthetic fiber having a single yarn fineness of 0.9 dtex or less, which is a feature of the present invention, is exhibited when 70 or more single yarns are discharged per one die. Below 69, the quality is the same as the base of the normal discharge hole array (see FIG. 3). For example, when the base of the present invention is applied when producing 33 dtex-72 filament polyethylene terephthalate yarn with one single thread, the quality advantage can be exhibited, but the 33 dtex-72 filament polyethylene terephthalate thread Is produced with a single base and one thread, the result is not much different in terms of quality from the base of the normal discharge hole array. However, even when the same 33 dtex-48 filament polyethylene terephthalate yarn is produced with two single yarns, the superiority of the quality of the fibers produced from the die of the present invention over the die with the normal discharge hole arrangement can be exhibited. On the other hand, the number of discharge holes is preferably 900 or less in order to satisfy the discharge hole interval and the discharge hole group interval described later.

  It is important that the base used in the present invention forms an aggregate of three or more discharge holes (hereinafter referred to as a discharge hole group) having a discharge hole interval S of 0.8 mm to 3.5 mm.

  Here, the discharge hole interval S refers to the distance from each discharge hole to the closest other discharge hole (see FIGS. 1A and 1B).

  When the discharge hole interval S is less than 0.8 mm, the polymer discharged from the die hole is fused with the polymer discharged from another discharge hole before being cooled and solidified, making stable yarn production difficult. Further, when the discharge hole interval S exceeds 3.5 mm, the quality superiority when spinning the ultrafine fiber, which is a feature of the base, is lost. If the discharge hole interval S is 0.8 mm or more and 3.5 mm or less, the conditions of the present invention are satisfied. However, the smaller the discharge hole interval S, the greater the number of discharge holes that can be drilled in one die. .

  On the other hand, in the present invention, it is important that the number of discharge holes included in one discharge hole group is three or more. When the number of discharge holes included in the discharge hole group is two or less, the quality advantage when the ultrafine fiber that is the feature of the base is spun is lost. Although there is no upper limit to the number of discharge holes included in the discharge hole group, the number of discharge holes included in the discharge hole group is preferably 6 or less in order to maintain the discharge hole interval of 0.8 mm or more. Further, in order to avoid polymer modification due to abnormal retention in the nozzle discharge hole and yarn breakage due to this, it is preferable that each discharge hole has an independent introduction hole. The relationship between the introduction hole and the discharge hole is shown in FIG. FIG. 5A is an example of “the discharge holes have independent introduction holes”, and FIG. 5B is an example of “the discharge holes have a common introduction hole”. Further, it is preferable that the discharge holes in the discharge hole group are arranged concentrically at equal intervals because the discharge hole interval can be increased and the polymer spun from each discharge hole can be cooled uniformly.

  In addition to this, it is important for the base used in the present invention that the interval H between the discharge hole groups is 5 mm or more and 27 mm or less. The interval H between the discharge hole groups means the shortest distance between the discharge hole groups belonging to one discharge hole group and the discharge hole group belonging to another discharge hole group. If the interval H between the discharge hole groups is less than 5 mm, the quality advantage when spinning the ultrafine fiber that is the feature of the die is lost. In addition, when it exceeds 27 mm, it becomes difficult to make the required number of discharge holes for a circular die having a diameter that is normally used. However, the arrangement of the discharge hole groups is not particularly limited, and a circumferential arrangement, a lattice arrangement, or the like can be adopted so that normal discharge holes are arranged.

  The shape of the nozzle discharge hole used in the present invention can be any shape. However, the shape of the Y-shaped hole, the cross hole, or the like where the discharge yarn is not bent directly below the nozzle shape as compared with the shape of the T-shape. A symmetrical shape is preferred, and a circular hole is most preferred. In the case of a circular hole, the diameter is preferably 0.07 mm or more and 0.15 mm or less. In general, when producing ultra fine yarn, the smaller the diameter of the discharge hole, the better. However, if the diameter is less than 0.07 mm, the discharge hole is likely to be clogged. It is necessary to take measures such as Moreover, when the length of the discharge hole is between 2.5 and 3.5 times the diameter, the polymer weighing performance is high, which is preferable.

  Furthermore, the die of the present invention defines the direction of the die when attached to the spinning machine so that the arrangement of the ejection holes in the ejection hole group is not aligned in the same direction as the direction of the cooling air used during spinning. This is very important. Hereinafter, the “state in which the discharge holes in the discharge hole group are not aligned in the same direction as the cooling air” will be described with reference to the example shown in FIG.

  FIG. 4 shows an example of the arrangement of the discharge holes included in the discharge hole group of the present invention. Assuming that the direction of the cooling air is in the direction of the arrow B, the parallel line in the air direction A is drawn from the discharge holes A, B, C, and D with respect to the vertical line X with respect to the air direction I. Line segment A1-A2, B1-B2, C1 corresponding to the diameter (width) of the discharge hole in the perpendicular X direction, where A1, A2, B1, B2, C1, C2, D1, D2 The fact that -C2 and D1-D2 do not cross each other is referred to as "a state where the discharge holes in the discharge hole group are not aligned in the same direction as the direction of the cooling air".

  In the case where the melt spinning method of the present invention is applied to a spinning machine having a uniflow type cooling device which is a general spinning equipment, the quality of the original yarn produced by the conventional spinning method when ultrafine yarn is produced. Is characterized by its superiority. For this reason, it is important that the relationship between the discharge hole array in the discharge hole group and the direction of the cooling air maintain a constant relationship. That is, when the discharge holes in the discharge hole group are arranged in the same direction as the direction of the cooling air, the polymer discharged from the base hole is cooled and solidified even if the discharge hole interval S is 0.8 mm or more. It will be fused with the polymer discharged from another discharge hole, making stable yarn production difficult. This is presumably because the discharged polymer sways in the wind direction due to the influence of the cooling air.

  In order to satisfy the above requirements, it is possible to adopt a method of assembling the base by attaching some mark to the base when attaching the base to the spin pack, but there are positioning pins or notches that fit the spin pack on the base. It is preferable that the direction of the base installed in the spinning machine is defined by inserting it.

  In addition, the distance from the base to the cooling air blowing position is an important technical point in producing ultrafine fibers. For the purpose of the present invention, the distance between the top of the cooling air blowing and the base (FIG. 6). It is important that the reference is 20 mm or more and 80 mm or less. When the uppermost portion of the cooling air blow exceeds 80 mm from the die, the solidification point of the polymer obtained by melt spinning the ultrafine fibers is generated at a stage before the cooling air hits, and it is difficult to exert the superiority of quality. On the other hand, if it is less than 20 mm, the temperature of the die surface decreases due to the influence of cooling air, and the stability of the yarn production is poor. In order to keep the temperature of the base installed in the spinning machine, it is preferable to provide an auxiliary heating device under the base.

  In general, when melt spinning a polyamide such as polyethylene terephthalate, nylon 6, nylon 66, etc., a two-step method in which an undrawn yarn wound at a low spinning speed of 2000 m / min or less is drawn into a flat yarn. Further, a method in which POY wound at a spinning speed of about 3000 m / min or more is drawn and twisted into a false twisted yarn, and a method of continuously drawing and heat-treating the spun yarn without winding up are adopted. However, the die of the present invention can be applied to any of these processes.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, the following evaluation was implemented as a scale which evaluates the quality superiority and the stability of yarn making which are the targets of the present invention.

(1) Thread uniformity: Evaluation scale for quality superiority Using a Worcester tester manufactured by Zerbegger Wooster, the thickness of the wound yarn is measured by a half inert test. evaluated.

○: Less than half-inert 0.9 ×: Half-inert 0.9 or more (2) Spinning: Evaluation scale of yarn-making stability 6ends × 4 pos (24 spindles) small spinning machine (generally with a cooling system from one direction) 1 hot roller (hot roller with separate roller: 90 ° C., spinning speed 2500 m / min, 6 turns), 2 hot roller (hot roller with separate roller: 140 ° C., 6 turns) Then, spinning was performed at a winding speed of 4500 m / min, and the occurrence of spun yarn breakage was evaluated in the following three stages.

    ○: Stable yarn production is possible when the yarn breakage occurrence frequency is 2 times / t or less (2 yarn breaks per ton of spinning amount).

    Δ: The thread breakage occurrence frequency exceeds 2 times / t.

    X: Yarn breakage occurs immediately after threading on the winder, so that it is practically impossible to produce the yarn.

Examples 1-3, Comparative Examples 1-4
Intrinsic viscosity (measured at 20 ° C. using an equal weight mixture of phenol and ethane tetrachloride as a solvent) and 0.67 polyethylene terephthalate chip (containing 0.30 wt% of titanium oxide as a matting agent) 6 ends × 4 pos ( 1 hot roller (hot roller with separate roller: 90 ° C, roller speed 2500 m / s) by a small spinning machine (24 spindles in total), a uniflow type cooling device extending from 60 mm to 1000 mm below the base and a spinning facility with a heating ring under the base. 6 minutes), and after the yarn spun at 2500 m / min is continuously stretched between 1-2 hot rollers by 2 hot rollers (hot roller with separate roller: 140 ° C., 6 turns). The yarn was produced at a winding speed of 4500 m / min. The wind speed of the cooling air flowing from the uniflow type cooling device during yarn production was set to 30 m / min. In addition, the bases used were of the several types shown in Table 1 (however, the discharge holes are all 144 holes, 0.12 mm in diameter, 0.35 mm in length) so that they become a flat yarn of 56 dtex-144 filaments after yarn production. The discharge amount was adjusted. Table 1 shows the yarn uniformity and the spinning stability of the obtained fiber. Among them, the base of the present invention is provided with a hole 3 for a positioning pin (installed so as to be fitted with a spinning pack) (see FIG. 2), and the cooling air flows in the direction of arrow A with respect to the base installed in the spinning machine. A spinning pack was set to blow. The arrangement of the discharge hole group was a circumferential arrangement similar to FIG.

  Examples 1 to 3 are examples in which the die of the present invention was applied, and both the yarn uniformity and the yarn forming property were good.

  Comparative Example 1 was an example in which a base having a conventional discharge hole arrangement (FIG. 3) was applied, and the yarn uniformity measured by a Wooster was poor. In addition, there was a tendency to be higher than in the examples of spun yarn breakage.

  In Comparative Example 2, the discharge hole arrangement was that of the present invention, but the discharge hole interval was too narrow, the polymer discharged during the spinning was fused, and the yarn breakage occurred immediately after the winding of the winder yarn. However, the yarn uniformity of the small sample that was collected was good.

  Comparative Example 3 is an example in which the base is the one according to the present invention, but the positioning pins are not used at the time of assembling the spin pack, and the discharge hole arrangement direction in the discharge hole group is set in the spinning machine according to the direction of the cooling air. . Although the yarn uniformity was good, spun yarn breakage occurred frequently.

  Comparative Example 4 is a case where a double square lattice array die described in JP-A-5-125609 is employed. Since the positioning pins are not installed, the discharge hole arrangement in the discharge hole group and the direction of the cooling air are mixed or not. In this case, although the yarn uniformity was good, spun yarn breakage clearly having a tendency to weight occurred and there were more yarn breaks than in the examples.

The schematic arrangement figure showing an example of the discharge hole arrangement in the discharge hole group of the present invention. The schematic arrangement figure showing an example of the arrangement of the discharge hole group of the present invention. The schematic arrangement figure which shows the example of the arrangement | sequence of the conventional discharge hole. Explanatory drawing which shows the relationship between the discharge hole arrangement | sequence in the discharge hole group of this invention, and the cooling wind direction at the time of installing in a spinning machine. Sectional drawing of a spinneret. 1 is a schematic diagram of a spinning machine.

Explanation of symbols

1: Discharge hole 2: Discharge hole group 3: Positioning pin hole 4: Introduction hole 5: Polymer flow path 6: Spinneret 7: Spin pack 8: Spin block 9: Heating ring 10: Insulating material 11: Cooling device (Uniflow) type)
12: Yarn C1: Example of the direction of the cooling wind C2: Example of the direction of the cooling air C3: Example of the direction of the cooling air A: Direction of the cooling air S: Discharge hole interval H: Discharge hole group Interval L: Distance between the top of the cooling air blowout and the base

Claims (3)

When producing an ultrafine synthetic fiber having a single yarn fineness of 0.9 dtex or less by a melt spinning method,
(A) having 70 or more discharge holes,
(B) A group consisting of three or more discharge holes having a discharge hole interval S of 0.8 mm to 3.5 mm,
(C) A base having an interval H between the discharge hole groups of 5 mm or more and 27 mm or less is used.
The cooling air blowing device under the base
(A) A uniflow type cooling device,
(B) The distance L between the uppermost part of the cooling air blowing and the base is 20 mm or more and 80 mm or less,
(C) A method for producing an ultrafine synthetic fiber, wherein the discharge hole array in the discharge hole group of the die is installed so as not to be aligned in the same direction as the cooling air for cooling the spun yarn.   2. The method for producing an ultrafine synthetic fiber according to claim 1, wherein all of the discharge holes use caps each having an introduction hole. In an apparatus for producing ultrafine synthetic fibers having a single yarn fineness of 0.9 dtex or less by a melt spinning apparatus,
(A) having 70 or more discharge holes,
(B) A group consisting of three or more discharge holes having a discharge hole interval S of 0.8 mm to 3.5 mm,
(C) A base having an interval H between the discharge hole groups of 5 mm or more and 27 mm or less is used.
The cooling air blowing device under the base
(A) A uniflow type cooling device,
(B) The distance L between the uppermost part of the cooling air blowing and the base is 20 mm or more and 80 mm or less,
(C) An apparatus for producing ultrafine synthetic fiber, wherein the discharge hole array in the discharge hole group of the die is installed so as not to line up in the same direction as the cooling air for cooling the spun yarn.

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