JPH09111533A - Production of polyester fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for industrially extremely stably producing a large-size polyester fiber having 20-30 denier single filament size according to a high-speed yarn manufacturing method. SOLUTION: The spinning speed is regulated to 4500-6000m/min and the spinning draft is regulated to 2500-45000 when melt spinning a polyester fiber having 20-30 denier single filament size after takeoff.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyester fibers having extremely large single yarn fineness by a high-speed yarn producing method with high productivity and stability.

[0002]

2. Description of the Related Art It is known that when polyester is melt-spun at a high take-up speed of 4500 m / min or more, fibers having practically sufficient properties can be obtained without mechanical stretching. The high-speed spinning method is a spinning method which has advantages such as high productivity, omission of steps, and reduction of energy cost. However, in such a high-speed spinning method, it is difficult to cool and solidify the yarn discharged from the spinneret in the case of an extremely thick fiber having a single yarn fineness of more than 20 denier, so that the spinning tension applied to the yarn is increased. There is a problem that the yarn is greatly reduced and violent yarn shaking occurs, and single yarn breakage and fineness unevenness occur frequently.

Conventionally, the problem of insufficient cooling of the yarn is to increase the amount of cooling air, to adjust the temperature of cooling air, or to use JP-B-63.
The solution has been tried by a cooling efficiency improving means such as a method of passing a cooling air in a straightened state as described in Japanese Patent Publication No. 14540, but a single yarn fineness of 20 denier or more In this case, it was difficult to solve them by these cooling means.

On the other hand, Japanese Patent Application Laid-Open No. 64-14314, Japanese Patent Application Laid-Open No. 5-230713 and the like disclose high-speed spinning of polyester at a high draft, but the purpose is different from the present invention. It is intended for clothing fibers having a small single yarn fineness, and does not describe high-speed spinning of large fineness fibers having a large single yarn fineness.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a method for producing a polyester fiber of large fineness having a large single yarn fineness by a high-speed spinning method which is industrially extremely stable and has good operability.

[0006]

Means for Solving the Problems As a result of intensive studies aimed at achieving the above objects, the present inventors have made it possible to stabilize a polyester fiber of large fineness even at a spinning speed of 4500 m / min or more by making a spinning draft extremely large. They have found that they can be spun and have reached the present invention.

That is, according to the present invention, the single yarn fineness is 2
A method for producing a polyester fiber is provided in which a spinning speed is set to 4500 to 6000 m / min and a spinning draft is set to 2500 to 45000 in melt spinning a 0 to 30 denier polyester fiber.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester referred to in the present invention is a polyester having an ethylene terephthalate unit as a main repeating unit, and the main object is polyethylene terephthalate, but within a range that does not essentially change its properties (usually 15 mol). The following) may be a copolyester obtained by copolymerizing the third component. Examples of the third component include dicarboxylic acids such as isophthalic acid, 5-sodium sulfoisophthalic acid, naphthalene-2,6-dicarboxylic acid, oxyacids such as p-oxybenzoic acid, propylene glycol, butylene glycol and polyoxyalkylene. Examples thereof include diols such as glycol.

The degree of polymerization of the polyester may be appropriately selected depending on the type of the polyester and the purpose of use of the fiber to be obtained. In the case of polyethylene terephthalate, the intrinsic viscosity (measured with an orthochlorophenol solution at 35 ° C.) is usually 0. ．
Those within the range of 55 to 0.75 are suitable. Further, these polyesters may contain additives such as matting agents, stabilizers, colorants, flame retardants and surface modifiers.

In the present invention, the above polyester is melted at about 270 to 290 ° C. and discharged from the spinneret according to a conventional method, and the discharged yarn is cooled and solidified by applying cooling air and then taken off to obtain a single yarn. A fiber having a fineness of 20 to 30 denier is used, but in that case, it is necessary to perform melt spinning at a take-up speed (spinning speed) of 4500 to 6000 m / min. If the single yarn fineness after take-up is less than 20 denier, the problem due to insufficient cooling is unlikely to occur, and therefore it is out of the scope of the present invention. On the contrary, if it exceeds 30 denier, the present invention is also stable. Cannot be spun into. On the other hand, when the spinning speed is less than 4500 m / min, the problem of insufficient cooling is less likely to occur, but the object of the present invention of industrially producing fibers with high productivity cannot be achieved. Also,
When it exceeds 6000 m / min, the problem of insufficient cooling cannot be solved even if the spinning draft to be described later is increased,
It is not preferable because the spinning cannot be performed stably. In addition, it is preferable to cool the cooled and solidified yarn as soon as possible in order to suppress the crystallinity of the obtained polyester fiber (undrawn yarn). For example, an oiling roller is placed at a position where the yarns are not fused to each other and It is preferable that the yarn is provided as high as possible above the spinning line and the yarn is rapidly cooled while also serving as an oil agent, and the undrawn yarn thus obtained is formed into a crimped yarn having a soft texture by subjecting it to drawn false twisting. You can

In the present invention, in addition to the above conditions,
The spinning draft is 2500-45000, preferably 10.
It is important to be in the range of 000 to 30,000.
If the spinning draft is less than 2500, the spinning speed is 4
In the high-speed spinning area of 500 m / min or more, the cooling of the yarn becomes insufficient, so that single yarn breakage and unevenness of fineness occur frequently,
The object of the present invention cannot be achieved. On the other hand, the spinning draft is 4
If it exceeds 5,000, the balance between the peeling of the molten polymer discharged from the spinneret from the spinneret surface and the spinning tension is disturbed, and not only a unique long-period fineness unevenness occurs in the fiber axis direction, but also a single yarn. It is not preferable because the cutting of is likely to occur.

[0012]

According to the production method of the present invention described above, the detailed reason is unknown, but the single yarn fineness is 20.
Even at a denier or more, the deterioration of high-speed yarn-forming property due to insufficient cooling is solved, and high-speed yarn-forming in an industrially stable operating state can be performed. Fibers obtained by such a method are, as they are, monofilament yarns for use in printing, shielding, etc.,
Further, it can be suitably used as a raw yarn for crimped monofilament to which false twisting is applied.

[0013]

The present invention will be described in more detail with reference to the following examples. [Example 1] A polyethylene terephthalate chip having an intrinsic viscosity of 0.65 was melted at a melting temperature of 290 ° C, and then discharged from a spinneret having six discharge holes having the hole diameters shown in Table 1. The discharged yarn was blown in a spinning tube having a tube length of 1.0 m so as to traverse the yarn at a temperature of 20 ° C. and a blowing speed of 1.4 m / sec. Distance 2.
An oiling agent was applied with an oiling roller installed at a position of 8 m, and the oil was taken through a pair of goded rollers at a take-up speed shown in Table 1 to obtain 240 denier / 12 filaments or 3
A multifilament of 60 denier / 12 filament (two compound yarns) was obtained. The results of the physical properties and the spinnability of the obtained filaments are shown in Table 1. In the table, the thread sway is shown by ◯ when it is hardly recognized, by Δ when it is slightly recognized, and by × (marked as XX) when it is mostly recognized. In the yarn production, those which are not recognized at all are indicated by ◯, those which are recognized a little are indicated by Δ, and those which are recognized by a large amount are indicated by ×.

[0014]

[Table 1]

Claims (1)

[Claims] 1. When melt-spinning a polyester fiber having a single yarn fineness of 20 to 30 denier, the spinning speed is 4500.
~ 6000m / min, spinning draft 2500 ~ 4500
A method for producing a polyester fiber, wherein the value is 0.