JPH1018122A - Melt spinning - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently carry out a melt spinning, eliminate an increase in size of a spinning mechanism due to a finer size of a spun yarn and improve the yarn quality by dividing a spinning hole group provided on plural concentric circles into each group of a prescribed number in the circumferential direction, forming plural groups and winding one multifilament yarn for each group. SOLUTION: A spinneret 1 having many spinning holes 3 is formed into one annular unit and a group of the spinning holes 3 provided on plural concentric circles are divided into each group of a prescribed number in the circumferential direction and formed into plural groups. The filaments are wound into one multifilament yarn for each group to perform the melt spinning. Air streams directed from the central part of a quench stack to the peripheral wall part are preferably jetted toward gaps among the spun yarn group in each group hanging down from a spinneret 1 and the spun yarn groups in the adjacent groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melt-spinning a thermoplastic polymer, and more particularly to a method for producing a multifilament yarn comprising a thermoplastic polymer in a small space at a low cost.

[0002]

2. Description of the Related Art In general, melt spinning of a thermoplastic polymer composed of polyester, polyamide, polyolefin, polyvinyl and the like, and a copolymer thereof is performed by introducing a yarn spun from a spinneret into a spinning cylinder. The spun yarn is cooled and solidified by the cooling air sent into the cylinder, and is then wound up as a multifilament yarn by a take-up device.

In the conventional mechanism of the spinning cylinder, a large number of spinning holes corresponding to the number of single yarns constituting a multifilament yarn are formed in a built-in spinneret. A structure in which a heating heater is attached to the outer periphery of each of the spinning heads attached to the spinning head formed in a square shape,
Or it has a heating medium heating structure. However, in the spinning cylinder having such a mechanism, the equipment area per spinning head is relatively large, and the heating between the spinnerets tends to be non-uniform. In recent years, a structure in which a large number of units are arranged in a straight line and the outer periphery thereof is surrounded by a heater is frequently used.

[0004]

However, in such a conventionally known spinning cylinder in which the spinnerets are arranged in a straight line, the number of spinning holes is increased due to the fineness of the spun yarn.
There are various problems as described below. That is, the first problem is that the spinneret located at the end of the linearly arranged spinneret is heated from three directions, while the central spinneret is heated only in two directions. The difference is that the thermal history of the spun yarn is different.

[0005] The second problem is that the cooling air coming into contact with the spun yarn is normally blown out in the horizontal direction with respect to the vertical running of the yarn, and when the spun yarn has multiple ends, This requires a long space in the width direction, which deteriorates the workability in various tasks.

A third problem is that there is a difference between the width of a single yarn row of a spinneret extending between long spaces and the width of a take-up device for winding the single yarn. When the filament yarns are bundled, it is necessary to sharply narrow the spun yarn into a fan shape, which causes a difference in tension between the outer yarn and the central yarn, which adversely affects the yarn quality. Such obstacles can be reduced by reducing the yarn bend on the yarn guide that guides the spun yarn, but this necessarily increases the vertical distance between the spinneret surface and the goded roller. As a result, the space in the vertical direction is increased.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional melt spinning method, and it is possible to simultaneously spin a large number of single yarns and multifilament yarns, and at the same time, to solve the problem. In this way, the production can be efficiently performed in about half the installation space.

[0008]

To achieve the above object, the first invention of the present invention has the following arrangement. That is,
After spinning a thermoplastic polymer polymer from the spinneret at the top of the spinning cylinder, contact it with cooling air to cool and solidify,
Thereafter, in a melt spinning method in which the multi-filament yarn is wound by a lower take-off device, a spinneret having a large number of spin holes is formed in one annular body, and the spinning is provided on a plurality of concentric circles. The hole group is divided into a plurality of groups in the circumferential direction by a predetermined number to form a plurality of groups.
It is a configuration characterized by winding as a multifilament yarn of a book.

According to a second aspect of the present invention, a single yarn group continuously spun by the spinneret according to the first aspect can be easily divided into groups. In the melt spinning method, the air flow from the center of the spinning cylinder toward the peripheral wall is injected toward the gap between the spun yarn group of each group hanging from the spinneret and the spun yarn group of the adjacent group. This is a characteristic configuration.

The thermoplastic polymer referred to in the present invention is a thermoplastic polymer which can be melt-spun, and examples of such a polymer include polyesters represented by polyethylene terephthalate, polycapramides and polyhexamethylene adivamides. And polyolefins represented by polyethylene.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. First, an outline of an apparatus for performing the method of the present invention will be described. FIG. 1 is a longitudinal sectional view showing the entire spinning cylinder, and FIG. 2 is a right half of a plan view showing an example of a spinneret.

In FIG. 1, 1 is a spinneret, 2 is a cool air blowing device as an auxiliary cooling mechanism, 3 is a spinning hole provided in the spinneret 1, 4 is fixed to a center fixing point 5 below the spinneret 1, A cylindrical plast candle of a main cooling mechanism which stands upright at the center of the cross section of the spinning cylinder, 6 is a cold air arm for sending cool air to the plast candle 4, and 7 is a guide and nozzle oiling device provided at a lower portion of the spinning cylinder.

As shown, the blast candle 4 as the main cooling mechanism supplies a cooling airflow in the in-out direction, and the cold air blowing devices 2 and 2 as the auxiliary cooling mechanism provide cooling air in the out-in direction. The former is the mainstream that always injects air, and the latter is the auxiliary airflow that is used when cooling is insufficient depending on the spinning type. Both of them come into contact with a later-described spun yarn 18 and are discharged to the outside accompanying this. The latter need not be used if the cooling by the former is sufficient.

The cold air arm 6 of the plastic candle 4
A primary cold air flow restricting mechanism 8 for adjusting the supply air flow is provided on the inner wall near the connection portion with the air supply, and a secondary cold air flow restricting mechanism 9 for similarly adjusting the supply air flow is provided at the center in the vertical direction. Is provided.

As shown in FIG. 2, the spinneret 1, which is a core component of the apparatus, is composed of a single annular body, and a plurality (11 in the present spinneret) of the annular body is provided. A predetermined number of spinning holes 3 are formed at substantially equal intervals on a concentric circle.
The spinning holes 3 are divided into a predetermined number (72 in FIG. 2) in the circumferential direction to form a plurality of groups (16 groups in the present embodiment, half of which are drawn in FIG. 2). A total of 16 so-called lane portions 11 in which the spinning holes 3 are not provided partially are provided radially from the center point 12 between adjacent groups.

As is well known, the plast candle 4 constantly injects the pressurized cooling air from the peripheral wall toward the periphery, and the auxiliary air injection device 10 mounted on the plast candle 4 is as shown in FIG. The secondary cold air flow restricting mechanism 9 is provided. The cool air adjusted to an appropriate air volume by the mechanism 9 is configured to be jetted from the radially protruding nozzle 14 formed corresponding to the lane portion 11 of the spinneret 1 toward the peripheral wall of the spinning cylinder.

Next, the configuration of the guide and nozzle oiling device 7 will be described. One for each group, corresponding to the three groups of spinning holes of the spinneret 1 divided into groups.
The guide / nozzle oiling device 7 is installed, and as shown in FIG. 4, a half of each is fixed to two semicircular connecting rods 15 provided horizontally below the spinning cylinder. In the case of this embodiment, the number of groups of the three spinning holes is 16
Therefore, eight guide and nozzle oiling devices 7 are mounted on the connecting rods 15 and 15, respectively.

The shape of the nozzle oiling device 7 is as follows.
In the present embodiment, a forked type having a guide port 16 shown in FIGS. 5A and 5B is used. 17 is a multifilament yarn 1 in which a spun yarn 18 is bundled.
9 are all oil supply holes, all of which are connected to the nozzle oiling gear pump device 20. However, the illustration of all the oil supply holes is omitted, and only the two connected states of the guide and nozzle oiling device 7 are shown in FIG. Show.

The method of the present invention is carried out by using the apparatus having the above-mentioned configuration, and the process will be described below. The following process shows a method for melt-spinning 16 multifilament yarns each having 72 single yarns at the same time and with the main cooling air flow in and out as described above. The method is
In FIG. 1, a horizontal airflow directed outward from the plastic candle 4 and a horizontal airflow directed inward from the cold air blowing device 2 are brought into contact with the single-filament spun yarn 18 discharged from the illustrated spinning hole 3. After cooling and solidifying this,
The plast candle 4 is lowered into a ring-shaped spindle that surrounds the periphery of the plast candle 4 and then bundled into a multifilament yarn 19 to be brought into contact with the guide / nozzle oiling device 7 for oiling. It consists of a winding process.

In such a melt spinning method, the nozzle 14 of the auxiliary air injection device 10 is located immediately below the lane portion 11 of the spinneret 1, and the spinning yarn 18 groups of each group are provided.
By injecting cold air from the central portion to the outside at the time of start up toward the gap between the group of spun yarns 18 of the adjacent group, it is possible to easily separate the multifilament yarns without causing fiber mixing. I can do it. In the above-described embodiment, the operation timing of the auxiliary air injection device 10 is set at the time of the spinning start sorting operation. However, when the main cooling depends on the in-out air flow, continuous operation can be performed. .

The auxiliary air injection device 10 is also effective when the main cooling of the spun yarn is performed in-out.
In this case, an air source for the auxiliary air injection device 10 is required separately from the yarn cooling, but in the out-in main cooling system, the spun yarn tends to concentrate at the center of the spinning cylinder, Even if multiple ends are attempted, it is very difficult to divide the yarn into a predetermined number of single yarns. However, it can be easily divided by installing the auxiliary air injection device 10.

In the method of the present invention, as is well known,
It is preferable in terms of yarn quality to increase the ratio L / D between the depth L and the diameter D of the spinning hole 3 and increase the discharge pressure.

As described above, according to the method of the present invention, a large-diameter annular spinneret is used when performing melt spinning. The yarn can be spun at the same time. Further, since the spinning holes of the spinneret are grouped, and the arrangement of each group is set at the same distance from the center, the heat history between the groups becomes uniform, and the fineness and dyeability between the yarns can be made uniform. Hereinafter, the present invention will be further described with reference to specific examples.

[0024]

EXAMPLE A polyethylene terephthalate having an intrinsic viscosity of 0.63 was heated at a temperature of 292 in a 90 mmφ / 24D spinning extruder.
C. and the polymer was spun at a discharge rate of 695 g / min from the spinneret 1 of the spinning cylinder shown in FIG. The spinneret 1 has a shape as shown in FIG. 2, and the diameter of the spinneret 1 is 340 mmφ in outer diameter and 233 mφ in inner diameter.
Group arranged. The minimum distance between the spinning holes 3 in one group is 4.5 mm, the minimum distance between the groups is 10.5 mm,
The diameter of the spinning hole 3 was 0.20 mmφ, and the L / D of the spinning hole 3 was 3.0.

The spun yarn (single yarn) 18 discharged from the spinneret 1 in the above process is bundled in each group, and is radially jetted outward from the plast candle 4 at a temperature of 30 ° C. and a relative humidity of 65%. It was cooled with air to form a 16-end multifilament yarn 19. Next, the multifilament yarns 19 bundled into 16 groups in the spinning cylinder are respectively brought into contact with a group of guide and nozzle oiling devices 7 shown in FIGS. And wound on an eight-end automatic winder (both not shown) installed in two upper and lower stages through two cold gosets.

The 16 POY polyester multifilament yarns thus obtained each had a fineness of 115 denier / 72f, a critical tensile strength of 2.5 g / d, and a critical tensile elongation of 128%. The fluctuation rate is 0.
4%, which is not inferior to POY obtained by the conventional method.

The auxiliary air injection device 10 mounted at a position 50 cm from the upper end of the plastic candle 4 in FIG.
In this method, the spun yarn 18 was divided into multifilament yarns 19 and jetted only during a working time period in which the yarns were introduced into the guide / nozzle oiling device 7 below the spinning cylinder. The amount of air was selected by adjusting the amount of air suitable for the sorting operation by the secondary cold air amount restricting mechanism 9. During the normal spinning time period, the cold air opening / closing link 21 was closed, and the injection of the sorting air was interrupted.

[0028]

As described above, according to the method of the present invention,
It is possible to solve the problems of the conventional method described at the beginning, and to melt-spin a plurality of, usually 8 to 16 multifilament yarns while preferably using one spinneret, that is, one gear pump having one port. Thus, the equipment cost of the apparatus to be implemented is significantly lower than that of the conventional equipment, and the equipment space can be reduced to half or less of the conventional equipment. Further, since the productivity is high, there is an effect that the production cost of the multifilament yarn can be significantly reduced. By the way, in the conventional method, when producing 75 denier of 1 dpf with 16 ends, the total installation space including the spinning head requires a horizontal space of 1.7 m to 2 m due to the distance between nozzles and the like. However, using the method of the present invention allows this with a small horizontal space of 650 mm.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entirety of a spinning cylinder for carrying out the method of the present invention.

FIG. 2 is a plan view showing an example of a spinneret.

FIG. 3 is a plan view showing the auxiliary air injection device.

FIG. 4 is a plan view showing a guide and nozzle oiling device group.

5A and 5B show a guide and nozzle oiling device, wherein FIG. 5A is a plan view and FIG. 5B is a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spinneret 3 Spinning hole 4 Plast candle 7 Guide and nozzle oiling device 10 Auxiliary air injection device 18 Spun yarn 19 Multifilament yarn

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[Procedure amendment]

[Submission date] July 31, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5

Claims (2)

[Claims] 1. A thermoplastic polymer polymer is spun from a spinneret on the upper part of a spinning cylinder, and then cooled and solidified by contacting a cooling air thereto. In the melt spinning method of winding as a yarn, a spinneret having a large number of spinning holes is formed in one annular body, and the spinning hole group provided on a plurality of concentric circles is divided into a predetermined number in the circumferential direction. A melt spinning method, wherein a plurality of groups are formed, and each group is wound as one multifilament yarn. 2. The melt spinning method according to claim 1, wherein a peripheral wall is arranged from a central portion of the spinning cylinder toward a gap between a group of spun yarns hanging from a spinneret and a group of spun yarns of an adjacent group. A melt spinning method characterized by injecting an air flow toward a section.