JPS58163714A - Preparation of flat yarn - Google Patents

Abstract

PURPOSE:To obtain a flat yarn having improved uniformity without causing a broken yarn and fluff, by melt spinning a thermoplastic synthetic polymer through specially arranged slit nozzles. CONSTITUTION:A thermoplastic synthetic polymer, e.g. a polyester, is melt spun through spinneret nozzles in a spinning pack positioned in a spinning block to make the longer sides of nozzle slits in parallel to the flow path of a cooling air in the direction of arrow.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for spinning a flat yarn of a thermoplastic synthetic polymer having excellent retention properties. .

In recent years, thermoplastic synthetic fibers have been widely used for clothing. Initially, the cross-sectional shape of synthetic fibers was circular, but as fibers and
In order to improve the texture and gloss of the knitted yarn, various irregularly shaped WE surface yarns have been developed.

Flat cross-section yarns have recently attracted attention because they develop a unique texture when used in knitted fabrics. It is certain that flattened melt-discharged yarns are cooled uniformly, and in the conventional production of flat yarns, yarn breakage occurs during yarn cooling due to irregularities in yarn cooling, and yarn breakage occurs during drawing. There was a problem in that there were many occurrences of blemishes, and there were also many uneven thicknesses and stripes, which lowered the commercial value.

The present inventor, Misaki, has conducted intensive research to solve the drawbacks of the conventional method, and has found that all of the above-mentioned drawbacks can be overcome by appropriately arranging the nozzle slit of the spinneret with respect to the cooling air flow path. After discovering the facts, we have arrived at the present invention.

That is, according to the present invention, a thermoplastic synthetic polymer is melt-spun from a slit nozzle:
This is a method for manufacturing a thermoplastic synthetic monomer flat yarn, which is characterized in that, when manufacturing the cjI flat yarn, the long side of the pattern nozzle slit is arranged so as to be parallel to the flow path of the cooling air flow.

Thermoplastic synthetic polymers used in Honjitsu T@ include homopolymers and copolymers such as polyester, polyamide, and polyolefin.

In addition, the synthetic polymer contains a small amount of matting agent and JI coloring agent.

It may also contain sardine additives such as necking agents and stabilizers.

In the present invention, a slit-shaped nozzle as shown in Fig. M1 (P) is used, but even if the nozzle has a modified monogamous slit shape as shown in Fig. 1 (B), the spun yarn has a flat #. This is the object of the present invention.

Conventionally, a nozzle with a cap nozzle in which slits are arranged in the direction of the center of a circle on one circumference, as shown in Fig. #I2, has been widely used.

Therefore, with the conventional nozzle, the long and short sides of the flat cross section of the ejected yarn and the cooling air ft1k! shown by the arrows! 1, the angle between the two threads is not one foot, and a cooling difference occurs between the discharged yarns.

Furthermore, the cooling air collides with the long sides of the discharged yarns, causing a phenomenon in which the cooling air becomes turbulent between the discharged yarns.

Under such cooling conditions, yarn breakage occurs during the spinning and drawing processes, which not only causes a decrease in productivity, but also causes the flat yarn obtained to be of poor quality, with many uneven thicknesses and fluff. Become. In the present invention, as shown in FIG. 3, the nozzle slit is placed in a spinning block such that the long side of the nozzle is parallel to the cooling air flow path indicated by the arrow.

The yarn discharged by this uninvented method of appropriately arranging the dK nozzle slit and the cooling air flow path has less yarn shaking (an extremely stable spun shape), and less yarn breakage in one machine (the resulting The flat threads are also of uniform quality with few thickness irregularities, streaks, and fuzz.

Hereinafter, the present invention will be explained in detail using Example 14.

Example Orthochlorophenol solution Spin boot polyethylene terephthalate with an intrinsic viscosity of 0.11i4G measured at 35°C! 11! It melts at 290℃ and has a shape as shown in Figure 1 (A), short side length 0.141111 + long side length le
A spinneret with 4 slits as shown in Figure 3 (15 pieces) was spun through a spinning bag installed so that the long side of the nozzle slit was positioned parallel to the cooling air flow path, and a flat yarn of 236 denier and 15 filaments was wound. ``There was very little swaying of the yarn during the cooling process, and there was very little yarn breakage during the spinning process as shown in Table 1.

The obtained undrawn flat yarn was heated at 85°C.
(1') Stretched to 3.25 times with a stretching machine equipped with a non-wk slit heater and a cold stretching roller, 72.
A flat yarn of 6 denier and 15 filaments was obtained.

As shown in Table 1, the thread breakage during drawing is minute, and the thickness of the thread is uneven (09
6) was good at 0.5 inches, and the level of one streak and fuzz was extremely low.

Comparative Example The slits were prepared as shown in Figure 2 (spun under the same conditions as the Example except that spindles arranged on the circumference were used).

A 1'P rolling process was carried out to obtain a flat yarn of 72.6 denier and 15 filaments.

When we observed the yarn shaking in the spinning cooling mill, we found that the single yarn was #II.
It was agitated from side to side. As shown in Table 1, the yarn breakage during the spinning and drawing steps was 11 times and zs times, respectively, compared to the example.

In addition, both the thread thickness unevenness (US) and the thread unevenness and fluff were at poor levels as shown in Table 1.

Streaks: The stripes are knitted into a tubular shape using a sock knitting machine, dyed with polyester Eastman blue at 100°C, and graded according to the following criteria on the TSE.

6 points Completely level dyeing 4 points Slight mottling' 3 points Slight mottling 2 points Fair mottling 1 point Strong mottling on the entire surface Fuzzing: 288 strands 200 skin with 0II machine/30 with 1IIl speed The number of fluff detected after running 10,000 votes is converted to 1 million votes.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figures 1 (b) and (b) are enlarged views showing examples of the nozzle slit shape used in the present invention, Figure 2 is a plan view of a conventional nozzle nozzle, and Figure 3 is a view of the present invention. FIG. Ya 2 Figure χ 3rX1

Claims (1)

[Claims] A thermoplastic synthetic polymer characterized in that when a flat yarn is produced by melt-spinning a thermoplastic synthetic polymer through a slit-type nozzle, the long sides of the nozzle slits are arranged in parallel with the cooling air flow path. Method for producing synthetic single-unit flat yarn.