JPS6035444B2 - Melt spinning method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for melt-spinning synthetic fibers having a single yarn weave of more than 1 denier and less than 2 denier using a weft-blown paper tube at a take-up speed of 3000 min. be.

Conventionally, as a cooling means for melt-spun yarn, cooling gas is blown out from one side of the spun yarn, the cooling gas is blown almost orthogonally to the spun yarn, and then the cooling gas is blown onto the cooling gas blowing surface. Two types of spinning tubes are widely used: a so-called side-blown spinning tube, which discharges gas from the opposing surface, and a circular spinning tube, which blows cooling gas from the entire circumference of the spun yarn.

Among these, the former type of horizontally blown paper thread tube has an open surface on the opposite side facing the cooling gas blowing surface and is easy to work with.
It is often used for melt spinning multifilaments for clothing, which have a relatively small number of single yarns. When melt-drawing is carried out using such a cross-blown yarn tube, when the single yarn weave of the spun yarn becomes small, single yarn breakage occurs during the spinning process due to slight turbulence of the cooling gas, and furthermore, the fineness of the yarn decreases. Spots and physical spots are more likely to occur.

This tendency becomes particularly noticeable as the spinning take-off speed increases. The present inventor has developed a method for melt-spinning synthetic fibers having a single yarn weave of more than 1 denier and less than 2 denier at a high speed of 3000 rpm or more using a conventional cross-blown yarn tube under normal conditions. When the fibers were cooled, we encountered the problem that not only were weaving irregularities and physical property irregularities occurring, making it impossible to obtain yarns of good quality, but also single yarn breakage occurred.

As a result of intensive studies to solve these problems, we found that by reducing the blowing speed of the cooling gas, outside air is sucked into the thread tube from the surface opposite to the cooling gas blowing surface, and the cooling gas blowing surface The inventors discovered that it is sufficient to provide a rectifying device on the outside air suction surface, and arrived at the present invention. That is, the present invention provides a method for melt spinning synthetic fibers having a single yarn weave of more than 1 denier and less than 2 denier using a cross-blown bran yarn tube at a take-up speed of 3000 min. A gas rectifying device is provided on a cooling gas blowing surface and a surface opposite to the blowing surface, and the cooling gas is blown from the blowing surface toward the successive yarns, and the outside air is also rectified from the surface opposite to the blowing surface. This is a melt spinning method characterized by cooling the spun yarn by suctioning it into the spinning cylinder.

Hereinafter, the present invention will be explained in detail with reference to the drawings. Figure 1 shows
FIG. 3 is a longitudinal cross-sectional view showing an example of a side-blown continuous thread tube used in the present invention. In the figure, 1 is a base, 2 is a cooling chamber, 3 is a filter provided on the cooling gas blowing surface B, 4 is a rectifier also provided on the blowing surface B, and 5 is a rectifier provided on the surface S facing the cooling gas blowing surface B. It is a rectifier. Ru.

The yarn Y discharged from the spindle 1 with a single yarn grade of more than 1 denier and less than 2 denier is stored in the cooling chamber 2.
The spinning tube is cooled by the cooling gas blown into the spinning tube which has passed through the furnace and been rectified through the filter 3 provided on the cooling gas blowing surface 8 and the rectifier 4.

At the same time, from the surface S facing the cooling gas blowing surface B, outside air is sucked and introduced into the spinning basket through the rectifier 5, and the rectified outside air also cools the spinning basket. What is particularly important here is to adopt cooling conditions such that outside air is sucked from the surface S facing the cooling gas blowing surface B. In order to draw in outside air from the opposing surface S, the cooling gas blowing speed may be set lower than the blowing speed normally used, so that the suction effect of the yarn traveling at high speed is activated.
By setting the cooling gas blowing speed to 30 cm/sec or less, particularly preferably from 5 to 25 cm/sec, outside air can be drawn in from the opposing surface S. If the cooling gas blowing speed becomes too high, the cooling gas blown into the spinning cylinder from the blowing surface B will be discharged from the opposing surface S, and the suction and introduction of outside air will not be performed, so that the spun yarn Single thread breakage, longitudinal unevenness, and physical property unevenness occur. By blowing cooling gas from one side of the hagi-de yarn and sucking in outside air from the opposite side, the blown cooling gas and the suctioned outside air are balanced, and stable spinning can be performed, resulting in a coherent yarn. It will be done. In the present invention, rectifying devices 4 and 5 are further provided on both the cooling gas blowing surface B and the surface S opposite to the blowing surface to straighten the blown cooling gas and the suction outside air to
It is necessary to make it work.

As the rectifying device, a device having a gas rectifying effect, such as a device consisting of a rectifying plate as shown in FIG. 2 or a honeycomb structure device, is used. FIG. 2 is a perspective view showing an example of a rectifying device used in the present invention, in which rectifying plates 8, 9, 10, 11, . . . are arranged approximately horizontally at predetermined intervals on side plates 6, 7.
... are provided in multiple stages, and gas is rectified by passing between these rectifying plates. Although it is preferable that the rectifying device be provided over the entire length of the cooling gas blowing surface B and the opposing surface S, it is sufficiently effective to provide it only in the upper half. As explained above, according to the method of the present invention, the single yarn weave 1
Fine twill synthetic fiber with a denier over 2 denier 30
When melting paper yarn at a high speed of 00 m/min or more, stable weaving is possible without single yarn breakage occurring in the woven yarn, and the yarn is of good quality with less irregularities in weave and physical properties. can be obtained. Hereinafter, the present invention will be explained in detail with reference to Examples. Examples 1 to 4, Comparative Examples 1 to 2360 -Polyethylene terephthalate (titanium oxide 0.6% by weight) with an intrinsic viscosity of 0.64 measured with a chlorophenol solution
) was extruded from a spinneret having 48 pores with a pore diameter of 0.27 at a temperature of 298 qo at a discharge rate of 27.5 m/min, and cooled in a cross-blown paper tube with a flow straightening device as shown in Fig. 1. It was cooled by changing the gas blowing speed variously, and then taken up at a take-up speed of 3300 skins/min and wound up in a winder.

The cooling gas blowing surface extended from the position of 9 points below the nozzle to 100 points below the nozzle, and a rectifier was provided over its entire length. The rectifying device used was the device shown in FIG. 2 in which the rectifying plates were provided in multiple stages, and the spacing between the rectifying plates was about 50 willows. On the other hand, for comparison, using a conventional side-blown spinning tube without the rectifier,
Spinning was carried out under the same conditions as in Example 2 except for the above conditions.

Number of single yarn breakages that occur in the twill yarn during the spinning process (times/day)
, and grade unevenness (U%) were measured and shown in Table 1.

In Examples 1 to 4 and Comparative Example 2, the outside air is sucked in from the surface facing the cooling gas blowing surface, but in Comparative Example 1, the cooling gas is blown out from the surface facing the cooling gas blowing surface, and the outside air is sucked. It was not done. As is clear from Table 1, according to the method of the present invention, a yarn of good quality with little unevenness and almost no single yarn breakage can be obtained.

Example 5, Comparative Example 3 Testing was carried out under the same conditions as Example 2 and Comparative Example 2, except that the discharge rate was 40.2 m/min and the take-up speed was 5000 m/min.

Number of single yarn breaks that occur in the spun yarn during the spinning process (times/day)
Table 2 shows the measurement results of , and texture unevenness (U%). In both Example 5 and Comparative Example 3, outside air was sucked in from the surface facing the gas blowing surface. As is clear from Table 2, according to the present invention, a yarn of good quality with little unevenness and almost no single yarn breakage can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of a side-blown spinning tube used in the present invention, and FIG. 2 is a perspective view of the flow straightening device shown in FIG. 1. Y is a paper thread, B is a cooling gas blowing surface, S is a surface facing the cooling gas blowing surface, 4, 5 are rectifiers, 8, 9, 10, 1
1 indicates a rectifying plate. O1 Figure 2 Figure

Claims (1)

[Scope of Claims] 1. When melt-spinning synthetic fibers having a single filament fineness of more than 1 denier and less than 2 denier using a cross-blown spinning tube at a take-up speed of 3000 m/min or more, cooling gas is blown from the side-blown spinning tube. A gas rectifier is provided on the surface and the surface opposite the blowing surface,
Cooling gas is blown out from the blowing surface toward the spun yarn, and also from a surface opposite the blowing surface, outside air is rectified and sucked into the spinning tube to cool the spun yarn. Melt spinning method. 2 Cooling gas blowing speed from the cooling gas blowing surface is 30cm
2. The melt spinning method according to claim 1, wherein the spinning speed is less than /second. 3 Cooling gas blowing speed from the cooling gas blowing surface is 5 to 25
The melt spinning method according to claim 1, wherein the spinning speed is cm/sec.