JPS6257913A - Polyester yarn for woven fabric - Google Patents

Abstract

PURPOSE:Polyester yarn for woven fabric, providing high-dquality woven fabric with a specific crossectional flatness ratio free from faults such as tight warp, tight weft, etc., obtained by subjecting polyester to melt spinning at a specific take-up speed. CONSTITUTION:Polyester is subjected to melt spinning at >=6,000 m/minuaste, preferably >=7,000 m/minute take-up speed to give polyester yarn for woven fabric, having 1.4-3.7 crosssectional flatness ratio of each filament.

Description

[Detailed description of the invention] Industrial applications The present invention relates to polyester fibers for textiles.

More specifically, the present invention relates to polyester fibers suitable for obtaining high-quality textiles without defects such as sink marks.

Conventional Technology Regarding obtaining fibers with practically sufficient properties only through the spinning process by melt-spinning polyester and taking it off at a high take-off speed, for example, Japanese Patent Publication No. 35-3104, Journal of the Japan Institute of Textile Technology No. 33 It is known from Volume T2O, pages 8 to T214, etc. According to this, in the case of polyethylene terephthalate, for example, when the take-up speed is about 5000 m/min or higher, the fibers obtained become close to fully oriented yarns (conventional drawn yarns). The yarn obtained by this ultra-high-speed spinning method is basically resistant to external disturbances such as cooling wind unevenness (<, not only shows a good U% value desirable for clothing, but also has a low orientation of the amorphous part. It is known that it has excellent dyeability, which is thought to be due to this.

However, the elongation recovery rate is lower than that of conventional drawn yarns, and when used especially for textiles, slight structural bundles that occur during spinning and winding tend to become apparent during the weaving process, resulting in minute gloss spots on the textiles. It has become clear that this causes a defect called a sink mark, which significantly impairs the quality of the product.

In order to improve this drawback, Japanese Patent Laid-Open No. 58-54020 proposes a method of specifying a relatively high ratio of the birefringence of the amorphous region to the birefringence of the entire fiber.

However, according to the inventors' study, the birefringence of the amorphous region does not increase at spinning speeds of 6,000 m/min or higher, and especially at spinning speeds of 7,000 m/min or higher, the birefringence of the amorphous region does not increase.
m/min or more, the specified range of the publication cannot be achieved,
The sink defect was not resolved.

In addition, Japanese Patent Application Laid-open No. 57-161120 discloses a spinning speed of 400
A method has been proposed in which polyethylene terephthalate fibers spun at 0 m/min or higher are heat treated at a high temperature close to their melting point to improve their dyeability.

The purpose of this method is to improve the dyeability of the fibers, and the heat treatment is applied to a degree that causes a large change in the microstructure of the fibers, so the thermal shrinkage stress of the fibers after heat treatment is extremely reduced, and the fresh water shrinkage rate is approximately 1%. The following is true. As a result, there is almost no shrinkage (width ratio) of the fabric width due to scouring and dyeing, and ground cracking defects occur on the fabric. Furthermore, it became clear that the texture became paper-like and the gloss became glaring, resulting in a loss of commercial value.

Therefore, high-quality fabrics using polyester fibers obtained by high-speed spinning have not yet been obtained.

Problems to be Solved by the Invention The purpose of the present invention is to provide polyester fibers suitable for obtaining high-quality fabrics free from defects such as sink marks when spinning polyester at a take-up speed of 6000 m7 minutes or more. .

Means for Solving the Problems The present inventors have completed the present invention as a result of intensive studies to overcome the drawbacks of the conventional methods and achieve the above object.

That is, the present invention is a polyester fiber for textiles, characterized in that polyester is melt-spun at a take-up speed of 6000 m7 minutes or more, and each filament obtained has a cross-sectional aspect ratio of 1.4 to 3.7. .

The configuration of the present invention will be specifically explained below.

The polyester in the present invention consists essentially of polyethylene terephthalate, and is obtained by a known polymerization method, but additives used in ordinary polyester fibers, such as matting agents, stabilizers, antistatic agents, etc. May include.

Further, the degree of polymerization is not particularly limited as long as it is within the range for normal fiber formation. Further, a small amount of other third component may be copolymerized within a range that does not impair the purpose of the present invention. Specifically, the main repeating unit is ethylene terephthalate, and the third component is an acid component such as isophthalic acid, adipic acid, 5-sodium sulfoisophthalic acid, bis(p-carbomethoxyphenoxy)ethane, or diethylene glycol or polyoxy. Ethylene glycol, 1.4
It is copolymerized with less than 5% by weight of a glycol component such as butanediol.

In the present invention, polyester has a take-up speed of 6000 m/
The starting material is a polyethylene terephthalate fiber that is spun in minutes or more and does not undergo a drawing process. If the take-up speed is less than 6000 rn/min, the development of the crystalline region of the fiber is insufficient, and the birefringence of the fiber is as low as 0.08 or less, resulting in poor mechanical properties such as low strength and elongation of about 60% or more. will remain. For this reason, various drawbacks occur when the fabric is used without being stretched.

For example, the tension experienced during weaving causes the fibers to be partially elongated, significantly reducing the quality of the fabric.

Therefore, the polyester fiber used in the present invention has a take-up speed of 6
000 m7 minutes or more.

Preferably, it is 6500 m7 minutes or more, and more preferably 7000 m7 minutes or more to obtain sufficient mechanical properties and 100'C dyeability.

In the present invention, it is important that each filament wound up has a flat cross-sectional shape and a flatness ratio of 1.4 to 3.7.

When the cross-sectional shape is not flat, for example, when the cross-sectional shape is a normal circular cross-section, a triangular cross-section, a triangular cross-section, etc., it is impossible to completely eliminate sink marks for the following reasons. was difficult. That is, in the process of investigating this problem, the present inventors carefully observed the sink defect areas of fabrics obtained using a normal circular cross-section spinneret, and found that the yarn cross section of the sink area was similar to that of the normal yarn section. It was found that it was deformed into a flattened shape, and as a result, locally strong reflected light was generated.

This flattening phenomenon is thought to be caused by the slight structural strain in the yarn longitudinal direction that occurs during high-speed spinning and winding being stretched by several percent during the weaving and scouring processes. However, as in the present invention, the cross section of each wound filament is originally flat, resulting in a significant reduction in local gloss spots in sink areas.

If the ratio of the longer diameter (distance from end to end) to the shorter diameter of the filament cross section, that is, the flatness ratio, is as small as 1.4 or less, sink marks in the fabric cannot be completely eliminated. . In addition, when the aspect ratio is 3.7 or more, although no sink marks are observed, not only does the fabric as a whole become highly irritable, but it also has a paper-like finish, making it unsuitable for use as a high-quality general-purpose fabric.

In order to obtain a yarn that satisfies the above-mentioned aspect ratio, for example, under the conditions shown in the examples, by using a spinneret as shown in FIG. 2, and making the aspect ratio of the nozzle approximately 3 or more and 15 or less. achieved.

Hereinafter, the present invention will be explained by examples.

Embodiment FIG. 1 is an explanatory diagram of the melt-spinning apparatus used in the present invention. After passing through the heating cylinder 3, the polymer exiting the spinneret 2 is cooled by cold air commensurate with the accompanying flow rate in the lower strong-air type cooling cylinder 4. It solidifies by cooling and develops a thinning point. Thereafter, each wheel yarn is collected by a refueling guide 6 and directly wound by a winding machine 7.

FIG. 2 is a front view showing an example of the spinning hole shape of the spinneret used in the present invention, and FIG. 3 is an example of a cross-sectional view of filaments spun from the spinning hole shown in FIG. 2.

[η)=0.61 polyethylene terephthalate as the first
Using the device shown in the figure, the set temperature is 300°C and the number of holes is 24.
The fiber bundle is spun from a spinneret, cooled and solidified by a flow of 22°C air perpendicular to the traveling direction of the fiber bundle from around the entire periphery of the fiber bundle, then a finishing agent is applied, and the fiber bundle is taken at a take-up speed of 7000 m/min. Table 1 shows Examples and Comparative Examples in which the fibers were spun to a fineness of 75 d.

These fibers are processed using Nissan Water Jet Loom (LW-
Weaving was carried out as a weft at a weaving speed of 550 m/min. The textile standard for gray fabric is a warp density of 100 threads/
1nch, latitude density 80 lines/1nch, gray fabric width 133
It was cln. The results of determining the weft quality and texture of this fabric after dyeing are also shown.

(Hereinafter, remainder 9) Experimental case 4.5 shown in Table 1 is an example of the present invention, and in these examples, no sink marks were observed at all, and fabrics of good quality were obtained.

Effects of the Invention By using the polyester fiber of the present invention, a polyester woven product of extremely good quality without sink marks can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an example of a melt spinning apparatus for carrying out the present invention, FIG. 2 is a front view showing an example of the shape of the spinning hole of a spinneret, and FIG. FIG. 2 is a cross-sectional view of a spun filament. DESCRIPTION OF SYMBOLS 1... Spin head, 2... Spinneret, 3... Heating tube, 4... Cooling tube, 5... Yarn, 6... Oil supply guide, 7... Winder.

Claims (1)

[Claims] Polyester is melt-spun at a take-up speed of 6,000 m/min or more, and each filament obtained has a cross-sectional flatness ratio of 1.4 to
Polyester fiber for textiles characterized by having a polyester fiber of 3.7